On the Minitrix, hopefully, the P.O. bent the retainer tabs slowly and be sure you bend them slowly, too. They will be much less likely to break.
And, BTW, I have many old N scale Atlas locos I left with Rapidos and actually changed a couple of mine I had converted to MTs many years ago back to Rapidos just so they are the way they were new. This included my original E8 I bought in 1967. I also left my original 10 or so Atlas cars I bought at around the same time with the Rapidos on them.
Doug