HP32Sii date... Or Frankenstein model?

[rprosperi]

It's almost certainly genuine and having a mfg. date earlier than formal introduction date (March '91) is not unusual, in fact if you think about it, it's actually necessary. By the 90's, a model's "introduction" meant that it was announced as available for purchase now, and often included some availability and source information, such as "...available now from EduCALC, Elek-Tek and College Bookstores...".

It took weeks to months for a device to be shipped from factory to HP warehouse, warehouse to distributor, distributor to dealer's warehouse, warehouse to individual stores, etc.

Presence of the early bugs and self-test add confidence to the conclusion that you acquired one of the earliest Nardos manufactured. While there is no fortune coming your way if you were to offer it for sale, it is relatively rare as the vast majority of the 32SII's had the later ROM.