A mistake that made me very happy. :-) :-) :-)

[rprosperi]

(11-16-2018 05:41 AM)Thomas Okken Wrote:  The only part that was from my original calculator was the back of the case, presumably so I'd still have the same serial number.

Exactly correct, as this determines the original mfg date, and therefore also your warranty period, support entitlements, etc. If further service or support is required in the future, you would still have the same 'original' machine info to give them.

I quite recently worked on an HP-41C that had been in for HP service at some point; HP replaced the front half of the machine (no idea what the problem was) but retained the original rear case (with s/n), I/O block and even the original black plastic sheet that separates the CPU board from the keyboard, and had even written the original s/n on the sheet. My guess is the front half and the sheet were separate 'service parts' and the repair process was constrained to replace the minimum number of parts.