Remember that the troop trials Enfields had many parts which were unique only to those rifles, and many of their components cannot be described as typical to anything but the trials rifles. I had one of these (also converted to sniper) and it was not hard to see why they were supposed to be condemned...replacement parts were quite special.
One thing that was interesting on mine was that the cruciform bayonet (which was for the earlier production rifles) would not fir onto my trials rifle.
The Canadian parts manual shows the waisted type front sight base as the typical two part assembly. It does show a one piece type front sight base (non-waisted), but does not give a NSN, so I am not sure if it ever became anything more than a drawing.
I know one guy who got a 41 LB and did find the Waisted protector for it. As for everyone else, it seems everyone's looking for them, so good luck to us all I guess...so it is a normal 2 piece setup then.