owlvamp,
You have a genuine Polish made copy of the Singer 834. A clone!!! There is nothing exotic about it. It was made around 1990 + or - a couple years.
First of all only the body is "all metal". The insides are stamped metal with plastic gears. It is identical inside to the Singer 834.
To smooth it out:
>you need to remove the top, 2 screws, clean and oil everything that moves or looks like it might move.
>remove the nose piece, 1 screw, clean and oil everything in there as it all moves.
>remove the bottom cover or case, clean the bobbin area thoroughly and oil everything that moves.
>remove the belt cover, 2 screws, check that the belt is good and not too tight. This machine has a plastic motor mount and can be broken by over tightening the belt. At least mine does.
Put it all back together and use it. That's about all you can do. ALL Singer attachments, and many parts will fit that machine. You can use the Singer 834 manual if you don't have one.
Joe