I would have been tempted to cut the sleeves off and turn it into a short sleeve or sleeveless jacket.

Black leather cream would have worked wonders on the rest of the jacket, providing it with the colour and the nourishment it needs. I applied some to a jacket I purchased in the early 90s and it came out like new.

Pocket linings can be fixed. I get quite attached to my jackets.

Nice, but you forgot the two handles either side   
Now you need a matching fleece beanie.

Welcome. I'd say the 66 is a pretty solid beast. Benefit of the electric machine is that one can use both hands to guide the fabric. I rarely use anything more than straight stitch and zigzag, what machine did you end up with?

I use them for cutting around pattern pieces on a large mat. The mat costs more than the cutter.

It's faster and produces a cleaner, more accurate cut. I wouldn't do it any other way now.

Cheap "Jakar Rotary Cutter" from "The Range", cost only £2.99. I've used it 5 times on full patterns and many other times for cutting curtains etc. It's still sharp and 28mm replacement blades are cheap at 10 for £6 on eBay. The only down side to this particular cutter is that the blade tightening nut has a tendency to work loose, requiring periodic adjustment.

Rotary cutting is the way to go IMO. Just get a large A2 sized mat (or larger).

I didn't know they made a free-arm version. Very nice condition, has to be said.

If it's just the end-stop, you can by a replacement metal "zipper bottom stop", that you just crimp on with pliers. Cut the old plastic off, position the new stop and just squeeze the pliers hard. I'm sure there are youtube videos on the subject.

Important thing is size. There is sometimes a number on the under-side of the zipper pull, No. 3 or 5 usually. You can buy the stops on eBay.

Alternatively, you can as you say, use a heavy-weight thread, just wind around a few times.

Another method is to melt the plastic using a soldering iron, maybe joining two teeth, shaping it such that the zipper won't come off.

Bit of a shame to ditch a garment because of something so small. Also bit of a shame to replace the whole zip when it can be repaired so easily.

Did you get it fixed? Did you order the part via the link?

I recently talked to a local 3D printer and they charge £30/hr to re-model a plastic part (including one print) and it typically takes over an hour. So long as they can measure enough of it.

Do you have any service or part manuals specifically for the 740/760 apart from the generic 700 series document?
I have a working 760G, nice machine, I would like to keep it running forever...