...I bought new, very expensive thread ( Superior ) and new, very expensive needles ( Superior ) to go with my newly serviced machine ( my machine won't tolerate Guttermans )

I'cw mentioned it before, but for me Gütermann thread has turned out the be the most even quality and trouble free of them all (sew-all polyester). I've had the top stitch and extra strength threads too and it is high quality. I have their cotton thread as well. The polyester threads leaves much less dust than any other brands. I like most mercerised cotton threads though and I'm not that picky, neither are my machines.

Do you have a simple straight stitcher or other machine for backup? Sometimes it can be the machine, not ideal for some types of work. The odd thing is the Gütermann thread, at least sew-all polyester. It's common for a machine not to accept top stitch threads that well; some need a special bobbin case for it.

You have to check the bobbin tension when switching to a new thread, they are all different, weight, thickness, smoothness. I guess your Innovis has auto tension for the upper thread?

My 900 just sews, nothing particular about it. The only annoying thing is the latch for the casing broke. To keep the hinged sides closed I use a string instead, it works and I haven't bothered to track down a proper replacement.

I have a 900 Nova. The stitch selection is not the largest, but the utility stitches are there. It runs fine, a few more plastic gears than the 700 series and earlier. That said, this  machine is the same standard as the 800 series, and the 900 is made to be extra portable with a handle on top of the machine, not just in the case. If something is wrong, a repair is well worth it. It weighs a bit less than the Records, but I think it's just as capable. I dare say it should zigzag perfectly, it has the tension mechanism and CB hook / race Bernina is known for. It's rahter forgiving when it comes to upper tension, but if you sew a lot with top stitch thread you might need to get the special bobbin case for thicker thread. The only reason I haven't is the price.

Before anything, I would clean and oil; the top of the machine (two screws) and top of the freearm comes off (spring release, upper left side behind the bobbin cover). Take out the needle and presser foot before the top of the freearm, it prevents scratching the finish. There are oil points behind the face plate. The bobbin case and hook comes out easily. There are a few tutorials on the web for light DIY service and repair if needed.

From my experience, it has the same stitch quality as the Records (which where the top models. I have compared to the 730 and 830, and didn't notice much difference. Bernina has neater zigzag than many other machines, new and old. 

Oh, that is spot on what I am looking for and in near flawless condition it's absolutely a bargain. The 1930s cabinets are nice too, I think I would be willing to replace my 201K23 for the look of the early type 201 with gear driven motor.

I think this is as good as it gets. There are some nice qualities in cotton too, but I don't know of any source at the moment. It will never be the same as genuine calf or cow hide leather, but it can be nice and it goes in the washing machine.

You can always change your mind later on, even getting a new machine if needed. I know two cases where someone got rid of their cast iron straight stitcher, a 201 and I think other one was a Husqvarna. A few years later they both regretted it terribly and tracked down the same model again. Some of us pack up the old machine and store them in a cupboard for safe keeping. It's fine whatever you choose, you don't have to do machine embroidery all your life :- )

I wouldn't generalize too much from one case of black silk. I guess there were various methods of dying fabrics black. Mariano Fortunay "Delfi" dresses are know to still be intact with out restoration work. They came rolled up in carboard boxes and to keep the crepe fabric nice it was recommended they were to be stored in the same way. Get the right quality carboard and tissue paper for the purpose and this storage technique works. There are odd cases were old silk garments have been found in unusually good shape, sometimes they have decided to keep on storing them in the same place because of the favorable conditions. In museum storage they are kept in special closets and drawers, in rooms with controlled humidity and temperature, but still wrapped in tissue paper.

A lady who worked with fabrics at a museum, (clothes, carpets, curtains,...) gave this instruction for someone who wanted to take care of an old item; it was either the cardboard box method, and another way was; To wash a white 100% cotton sheet on 95C with washing powder, then another round in the washing  machine at 95C with out any detergent. This was to be dried with out being ironed just strethced and smoothed out when wet.  You had to go through the double wash even on brand new sheet as well as and old sheet you might have. The point was to have reasonably sturdy woven cotton with out traces of fabric softeners, detergents, or anything left over from production. It  had to be white and no dyes in the fibers. The garment you wanted to store safely should carefully be rolled up or wrapped in the sheet. It was an alternative when it was difficult to fit things in a box or store a large enough box.

There's something called equa fleece, a type of waterproof polyester fleece. It can be handy. I am used to dalmatians and golden retriever. Male dogs need different parts of the coat free or open than freemales, when you make your own it's easier to adjust. I have lined the dog coats with polester blend woven wool materials; I took the chance and just threw it in the washing machine at 40C. I used non enzyme detergent, and it has held up fine. The water proof materials I have found are thin and not very warm, and need to be line for winter wear. I have bought large dog coats on sale and altered them.

The trick is to get a good fit dog, velco straps or shoe laces to keep it in place. Some dogs are more active than others, you just have to try and maybe make improvents along the way.