Shortage of Mk2 spares.....? It really all depends on what you a) mean or b) want to do or c) need Tom. The overriding aim when the simplified Mk2 gun was introduced was that the components should be fully interchangeable between the two types (there wasn't a Mk3 then of course). Generally speaking, they are. If not as COMPONENTS, then certainly AS ASSEMBLIES; pistons, gas plugs, butt slides, trigger mech parts, butts, bipods etc etc etc. So it would be a pixx-poor Armourer who couldn't keep a needy gun on the road.
If it's specific Mk2 parts, such as, say, a Mk2 butt or piston or trigger then Forumers should take heed of the ACI that details the intro of the Mk2 gun in June '41......
The Mk 2 Bren gun was introduced into service under the authority of the Army Council LoC B-4877 of 6th June 1941 with a VAOS number of C1-BE 4160. It was described as:
‘The above-mentioned pattern of Bren gun is hereby introduced, the design being simplified to facilitate manufacture. The Mk2 gun is in principle the same as the Mk1 and all the main assemblies, in addition to several components, are interchangeable. The main differences are as follows: (Authors note; this detailed explanation follows in text).
During the process of changing over production from Mk1 to Mk2, several Mk2 guns will be fitted with Mk1 assemblies and components and Mk1 guns will be fitted with Mk2 components and assemblies. For the purpose of taking on charge etc., the gun will be either Mk1 or Mk2 according to the marking on the body.
A number of components of the Mk2 gun, although different in design, are nevertheless interchangeable with the Mk1 gun and these are indicated within the VAOS’.
If it's a case of what you NEED, then it's worth looking at para 2 of the ACI because it states quite clearly, for all to see, that even during its introduction the guns will be a hybrid of Mk1 and 2 parts. Indeed, later in UK service it became an even greater hybrid with short barrel sets and Mk4 butts. So those originality freaks wanting a total Mk2 gun, parts an' all, have got short shrift from no less than the Army Council!
We're left with the solitary pistol grip. But even then, the conversion is a piece of cake. But whether an originality freak would want a make do and mend pistol grip is quite another matter. Now come a bit closer and don't tell anyone I told you this But 200 apparently happy UK deactivated Mk2 gun owners have them - so far