Looks really cool. I think it would be fairly easy to fix the lower barrel to its original length.
Could you show the back of the endo? If it has damage on the back-plate, then it is either an authentic or sourced from a Lucas Francis kit. If it is clean - fixed - it may be from something else.
And am I seeing it right: is it standing on its own?
EDIT: I think it is safe to say that it is not from the eighties. It sports the T2 design, so must be post '91.