Sadly I can't contact the engineer, he's retired.
There seem to be fewer and fewer knowledgable engineers in my area that I would trust with this machine. 

Well this is the thing. It has recently been serviced. This is how it was when it came back.
The engineer was encouraging me to replace it 

It's a Star Series, not sure of the model from your photo but this article might help with your identification:

http://www.ashleyandthenoisemakers.com/blog/2015/6/21/elna-super-64c-review

It discusses both flatbed and freearm machines.  HTH.

I have a set, it's like Christmas morning. I  have adapters for all my machines so they are universal snap ons. The cut out areas in the box for the individual pieces are well shaped and supportive.  The kit comes with a CD about usage and even special instructions on how to open the box 

I would recommend it, because with the exception of a walking foot it has most presser feet you could want, I won't say everything because that could of course be wrong!

If you want to go barefoot and use no presser foot can I suggest you reinforce your fabric with a suitable stabiliser so it doesn't all go down through the needle plate?

But... I thought an industrial SM is defined as a machine that usually is astonishingly fast, has just one function (eg straight stitch or buttonholing), an external clutch motor and needs plenty of space because of the size of the table, etc., and a technician in attendance to make any adjustments? Also, try moving one! In truth, a purely domestic application would be silly, I think.

Seriously though, it is marketing speak as pp have said to the uninitiated and I guess the moral of the story has to be 'Buyer beware'. Personally, if a poor metal domestic machine had spent its days in a surfer dude's bedsit mending sails or repairing motor bike seats, I wouldn't want it.

I'm generally practical but I would love to find (incredibly cheaply) a Singer two thread embroidery attachment, called a Simanco 35505.  They seem to be like hen's teeth but a real thing of beauty -

Here in all it's glory

Could there be someone out there who could retro-engineer them?  I'd be first in the queue!

The herd chez moi:
Bernina 930 bought new in 1984, an absolute rock, my desert island machine, and for a long time an only child
Bernina Virtuosa 150 QE made 1999, bought her second hand for quilting and reprogrammed her which was a thrill
Bernina 707 Minimatic I got because it was like my grandmother's that someone stupid gave away after she died
Singer 201k Mk2 handcrank from 1959 I got because it was like my mother's that was also given away 
Singer 99k handcrank/treadle from 1917 because she is so old and lovely and does the best straight stitch of any in the herd
Singer 431G (1964/5) free arm with chainstitch function, arrived stripped by the seller of any accessories or bits like a bobbin slider plate and foot controller so this is my restoration project in a small way for the next few weeks
Grain Mk2 a British made toy machine from 1963 that will do chain stitch and is very retro cute when she doesn't buck me off
('Collictivitis' now gaining quite a hold I think you can agree)
Elna Lotus SP from 1975, a little minx, still channelling the cute theme
Elna Supermatic 62C with a shedload of very sexy cams, and who wants a Necchi Supernova to come and live with her
Bernina MDA 1500 Overlocker, we are still working out who's boss, she and I
Janome Coverpro 2000 Coverstitch, we're good friends and whisper together about the overlocker when she's not looking
Janome Embellisher from someone very nice on this forum, being used to make C'mas decorations at the moment
Bernette b35 bought for daughters but surprisingly fun and up for it so she may join the breeding programme right here

I don't think I have missed any out, yet you can see I am a Necchi short but I can't decide which model - Supernova Automatica or Ultra?  Grateful for any suggestions on that or another machine entirely.

ETA: I suggested a FW to myself that I came across purely by chance yesterday (yes, really) so the Necchi will have to wait.  I said to myself for ages that a FW does hardly anything except straight stitch and look cute but suddenly all that was forgotten and I had to have it.  OH to his enormous credit has not suggested that another must go to make space