HP-19C with a strange S/N

[Ernst Fueloep]

Hi,

I have a HP-19C which has a very strange serial number:

0000A02260

Has anybody seen this?
What is the meaning of it?

See pictures.

The battery contacts are broken. I never saw this before on any HP-19C.
Because of this I am currently unable to verify if this unit works or not.

Here is the serial number close up and rotated 180 degrees for easy reading.
I have never seen such a serial number.

What is it? Is this some kind of prototype?

[Juergen Keller]

My guess is that it is a prototype. The 4 zeros are also mentioned in another thread about 71B's:

HP-71B Early Date Code