I'm really on two different thoughts on that black paint.
1- It was a cheap and easy fix for ho hum finishes put on for resale purposes when the rifles were surplussed. I have a NoI MkIII from 30 years ago and couple of martinis from the same period, picked up at Lever Arms, that were blued, not painted. It seems to be a recent thing.
2- It is a legitimate substitute standard finish and shouldn't be touched, or left on if the rifle isn't going to be shot, but collected, to enhance value further down the road.
There is little if any information anywhere.
The same thing can be said for the POFNo4 Mk 2 rifles that have recently become available. Of the several I've viewed, they are all covered in a matte brown finish. I mean covered completely, other than the bore and chamber.
They all have numbers painted on the fore or buttstock, underneath this coating. I really wonder if this is an anti glare finish or a preservative that has hardened to a laquer type finish and is meant to be removed.
Not trying to hijack your thread, and I apologise if you feel I have. I will delete it if you feel trespassed upon.
I feel that your question pertains to the information we both require and would really appreciate more feedback to both of our questions. As of now I haven't seen any real evidence but a lot of conjecture from some very knowledgeable people.
bearhunter