Ok, here we go! Thanks a bunch to tiriaq and to FALover for some parts and great advices!!
This was an interesting exercise for me. Never took one of these apart before. Lots learned.
Got some parts from Numrich as well. The gas cylinder was a good idea, the one I got is in great shape and price was reasonable ($90 US). The cheap stock set was, well, cheap in both sense. Inexpensive, but needed lots of fitting work. It's an "modified from Terni". It has a bend towards the back. Only realized this later, after much fitting

so I won't be returning it to Numrich. But hey, for a first one, it'll be ok until I decide to get a better stock.
Complete disassembly proved necessary for a good cleanup.
http://i1024.photobucket.com/albums/y310/lousen550/misc%20projects/HPIM8250_zpsehzj###g.jpg
A few indentifying numbers...
The obvious mishape at the back (still need to stain that part which needed to be flattened)
Almost done.
Hope I can find the time to test this one out soon...