What is stamped on the left side of the receiver and wrist?
In the USAI think you can get good no4 mk2s complete as issued for very reasonable money. If the metalwork really is in good nick, has a full barrel (5 groove?) and that includes the rifling in the barrel and you are prepared or want a fun project because you like doing that sort of thing (like me) then yes go for it. I have seen some lovely restoration projects on here, something of a challenge.
Parts via online stores and ebay seem quite plentiful and reasonable money in the USA. I would aim for a stock that isnt "reconditioned" if you can.
I would try and talk the price down though.
;]
regards