Mirkko,
Welcome to the QB.
Your machine is not uncommon, or an antique. It is a bit different since it has a matching hand crank attached and to some folks that does add a bit of value. I know if I'd found it in my attic I'd be tickled silly.
It's greatest value is as a really good sewing machine.
My manufacturer chart skips right over the J-C 20 code. And it doesn't list the LIBERTY brand either. So I can't help as to the maker. Is there an additional J-A number on it somewhere? That might help.
Joe
Last edited by J Miller; 07-16-2014 at 06:51 AM.