I seem to have got the industrial machine working!! I found a service manual for it online and after a few hours of cursing and breathing in the awful fumes from the oil that sits in the reservoir underneath, it seems to sew. The timing was all out of whack but after reading the instructions for fixing it about a thousand times, I finally worked out where the timing marks on the needle bar was, and then what the sewing hook was and the problem was a little arm that's meant to hold the bobbin in place. I couldn't unscrew it to move it, but after hours of trying, I got the chisel out and bent it a little today and the bobbin seems to be staying and I just sewed a piece of fabric and the stitches look good. Hopefully it stays like that. Man it's scary fast when it goes!!
Actually just went back and tried again. It sews 16 layers of calico without blinking!
Got a few little things to adjust. Looks like I may be able to slow it down a little by adjusting the foot pedal which would be nice. The upper tension is a bit loose and the tension dial is broken, but I'm hoping I can steal the one that's on the other Singer I have which doesn't like me.
Here's what she looks like... (complete with most of the tools I own)
And what she does...
Am back an hour or so later to offer a word of advice to fellow wanna-be sewing machine mechanics. Fixing the tension dial is not something to be undertaken unless absolutely necessary. It's easy to break. I think though that with some tricky threading* I've got it working. It doesn't help that it's missing a bit, or two. Oh and the foot pedal adjustment idea worked. I can get it to just sew a stitch or two at a time now instead of about 5cm of stitching before I've even started!
*Now, I don't actually know how to thread the machine (just taking a guess), so what appears to be tricky threading, may actually just be the correct way to thread it... Who knows?