HP-27S 50th Anniversary Limited Edition really?

[Allen]

This is an interesting find!

Maybe some things to consider when evaluating whether this is a prototype:

1. The color of the badge is different, decreasing the likelihood of a face/plate swap
2. Check the 4 posts in the battery compartment for any signs the calculator had been opened post-manufacture
3. Check around the edges for any evidence the case front was pried apart (or bent faceplate)
4. Check to see if the ROM ID is consistent with others made in the same time frame.
5. Check the Serial Number (eg. 9999.. would suggest prototype)
6. Check the provenance of the owner. The closer the seller lived to Corvallis, OR, the more likely an unusual item is legitimately rare/original.
   

Any evidence that the case was opened might suggest part swapping and not a prototype. I've seen several auctions over the years that claimed to be "rare prototypes" but upon evaluation (self test, ROM ID, repair evidence, keyboard label layout, etc..) nearly all were actually some home repair to save an expensive calculator rather than a rare prototype.


Evaluating based on information so far:

(True = Likely prototype, False= Likely not prototype)

1. True
2. UNKNOWN
3. UNKNOWN
4. Assumed True ( I don't know the production dates of ROM A)
5. False
6. UNKNOWN
   

Nice find!!