Re: HP Police -- yeah, I suppose they could. I didn't mean to make this sound like a major operation, though. I've done it twice, and the two "HP-142BS" (-14B/-42S) models are so inconvenient to use, I'm not sure the result was worth it. (I should have kept one of the replacements rather than sell them both!) The intent of the story was to emphasize how serviceable the Pioneers really are. Even the mechanical parts of the keypad may be renewed, assuming the keys are still attached to the calculator front.
Re: the meltdown option, I think the serial number would give that one away, and without a proper serial number for the damaged unit, I doubt I'd get a replacement.