Hey Dlask, lovin the Bren thanks again!
An American Bren owner on Reddit said this to me, FYI - just passing along:
Let them know there is a huge American market for those parts also. Not sure what the import laws look like for "parts", but there is definitely demand for those same parts here. There is one American company making barrels in different lengths and calibers, but they are doing the same thing and having to reuse the original barrel extension (trunnion), gas block, etc. Leaving people with a barrel that's essentially useless.