Vintage year?

[FGRABNER@eldec.com (FGRABNER)]

With the recent topics of identifying year of manufacture, I've always been
curious about mine.  I have a dunb question, however.  Where do I find the
serial number of the organ?  Mine was originally a C-3 that has been cut to
a "portable" cabinet i.e. no original nameplates remain.  It has:
- "Smooth" chorus wheel
- No info at all stamped on the drawbars
- Rounded over drawbar tabs (as opposed to squared off)
- Fairly small and unpretentious "Hammond" lettering between manuals
- Real wood keyboard end blocks
- Silver transformer on preamp
- "Longer" silver painted wood delay line that doesn't mount to rear of
manuals but hangs from above in the original cabinet.

Anybody want to take a stab at the year?  Are there some numbers located
somewhere on the preamp or generator that would help?
Thanks