Hello Vallo, I admire your willingness to improvise, these guys keep telling you to spend money, which cannot be avoided sometimes, but if your have more time and skill than money, you will still get there.
I have a 135 mm Tominon in a shutter marked Polaroid MP-4, but the shutter is stuck open. The glass is perfect, lenses are spotless.
If you think that you can find a repair guy who knows how to work on shutters, I will send it to you.

Chris