Come-on Boomer, it's not heavy. SKSs are light.
First off, welcome to the boards.
Looks like you have a Chinese Paratrooper(at least that is what it came into the country as) that has been stripped of its bayonet, mag, and stock. The stock it is in now is a Combat Exchange/ATI Ultra Light folding stock. Steel detachable mag(YMMV as to how reliable it is) and a twist on FH. If you have all the original parts it would be worth more if you restore it back, but it's your rifle so set it up as you like it.
As for the action. It looks like a /26\ 1967, but can't see the factory code real well in the pic. It would have been a regular /26\ that was refurbed and modified into a Paratrooper for import into the US. In case you didn't know Paratrooper SKSs were never actual military set ups. Just something the Chinese did to increase sales.