Just a gueery on those replacement barrels are they going to have the bayonet lugs on them, I am not real certain but I think MAB do the No.4 barrels in the parkerised without the bayonet lugs if you want to be semi pure you can have them put on as an extra.
There is another mob doing chrome moly Mk III barrels in stainless thinking of getting one as the standard profiles are hard to come by in any condition I got one complete from Canadaicon 11 years ago but they sure have been scarce on the ground still I reckon theres people in the know that have inklings of where they are.

Years ago in one of our deserts in the West Au here a drilling exploration friend said they lost a drill rod down a hole when outa the blue some bloke rocks up with a bren on the bonnet of his SWB landie apparently WWII stuff was bunkered there and forgotten, do not know how true but a good yarn all the same.
I only managed 1 range session with the Bren and it was hell accurate a very narrow cone of fire and proportedly had the nice act of dragging you forward still it was very nice to shoot even on full auto just good old weapons manufacture