I was wrong
The ones I have with the removable base plates are Wilson Combat Low Profile magazines and I checked even though they are Low Profile they are too long so they wouldn't be WB legal.
When I bought them many many moons ago the base plates were thin metal that fit inside the magazine and held in by the rolled sides of the magazine body. These mags do not have slots cut into the sides of the magazine so that style base plate will not work.
I can't get to my Tripp mags at the moment so I can't verify the base plates but looking through my paperwork they are P/N 7R-45-WG which have welded base plates.