Woodstock with serial number in battery compartment

[PANAMATIK]

(11-27-2016 02:02 PM)Harald Wrote:  Which Woodstocks had the serial number in the battery compartment?

I can stretch the range of these early models with my HP-21 serial number 1505S18699. You didn't mention, that the case doesn't have engraved a serial number at its usual place. Thus you can distinguish these models from outside.

Bernhard