HP 48G with 128K RAM?

[Siegfried]

When deciding which of my two HP 48Gs to sell after getting a GX and a G+ I found that one of them indicates 128K RAM. I bought it used a couple of years ago and don't have a contact for the seller. I can't remember it being advertised with extra RAM. It shows no signs of having been opened. It has 48G and "32K RAM" printed above the screen. Its serial number is ID74002727, ROM Rev. R.

While the 128K would make the decision which one to keep easy (and make my purchase of a G+ rather unneccessary) it does raise some questions:

• Is there any way the memory indication (MEMORY menu, SIZE) can be faked/wrong?
• should I assume the calc has been "user modified" (hacked)?
• are there other known 48Gs with more than 32K RAM?
  

Thanks for any hints.