The slabs are actually PCGS slabs with a PSA insert.
They are part of the same company, so it would make sense to do something like this
PSA and PCGS are related companies? Dang and I thought I was pretty in the know on the grading companies. Chibitcy and I were just discussing this subject the other day & how we were surprised that PSA never did their own coin slabbing and come to find out they have been the whole time I just didn't know it!!
They are both part of Collectors Universe, which is the parent company to PSA, PCGS, WATA Games (game grading) and now Goldin Auctions
Similarly, NGC is part of the same company as PMG (note grading) and CGC (comic and magazine grading)