Are L-E N4 Savage (U.S.) and Long Branch (CDN) parts identical

[Lee Enfield]

I wonder if stock parts made by Savage and/or Long Branch are readily interchangeable between N4's rifles of both origin ?

Also what's the purpose of the fiber wad resting against the large buttstock screw ?

Tanks in advance.

Interchangeable - yes; Identical - no.

There are also machining changes between early and later parts of the same manufacturer.

The progression of machining changes of a Long Branch receiver is pronounced during the production cycle.

One of the best examples of this is the "cut off" projection on the right side of the receiver.