I have seen a couple of mounts that have used two small runs of weld to secure the T shaped bracket to the flat on the top cover. (still with the 2 tight rivets)
One is at the front just in front of the elevating adjusting screw position and the other is at the centre at the rear.

The few I have seen done like this look to have been done in a uniform manner (all in the same place, same amount of weld, and same quality of weld,) and all the mounts have been re finished just like the originals.

I don’t know if this was an original in service repair or an after market reproduction but they do look consistent with service use.

---------- Post added at 09:49 AM ---------- Previous post was at 09:40 AM ----------

Also…….
I have just taken apart some IWS Top cover mounts for the L1A1 the top covers were very badly damaged but the mount and tabs were worth saving to spot weld onto new top covers (when I find them)

Any way these mounts were spot welded to the top cover just like the suit mounts, it also looks like the mount and tabs were also silver soldered after the spot welding.
A bit of belt and braces….

As armourers my say “Make all sure”