Dual Density HP 82106A Memory

[aj04062]

I just got a 41C with two modules marked:
Dual Density RAM SVS 0012
Dual Density RAM SVS 0013

They have been clearly modified from originals, but I cannot tell what makes them different.

I have run SIZE 000 and the calc reports back 64 more registers (127). This is what should be expected with a std 82106A, correct?

If you know what the story with these might be, let me know. I may pop them open to dissect.