thanks for the swift reply. I tried it with a bolt and nut and some beafy piece of steel and just put tension on the inner bit... A few "gentle" taps with a plastic hamer did the trick.
I got the machine working again but it needs some little TLC still:
1. the presser bar doesn't fully come down. most likely some corrosion on these parts aswell. Helping it by hand will get it down all the way...I suspect the slide which lets the presser bar come up when one uses the lifting lever. It has a rod mechanism which is most likely to snug a fit...or maybe some dirt or dried up oil as well.
2. the end where the pulleys are is making nasty noises. the see saw arm (top bit) has some roller bearing on it and it runs inside the pulley wheel. I have to check that piece again. Maybe it is not clean enough.
the roller bearing seems to have the tendency to get stuck/catch on something on some places in that grove. Not sure how to tackle this problem.
3. I need to figure out some way to mount a motor to it.
I have sitting a 0,25 BHP electric motor with a 35 mm pulley on it. The motor is designed to run at 3000 rpm max. So I probably need some sort of reduction gear system to slow the beast down.
I was thinking of using some hard wood wheels and some bicycle main crank bearings (very strong pieces of kit), some bolts/nuts/washers, some leather belts (mainly used on threadle systems) and some pieces of hi end plie wood sheet for construction. Maybe even the far sided surface of the machine ( the area underneath the side handwheel) can be used to mount the reduction rig to it ?
Wish me luck chaps... From the looks of it she is not yet sewing leather any time soon.
PS: do comment or suspend the advice you guys think is needed....