I sat down this evening to start the project - project page on Hackaday.io, schematic, etc.

It turns out that before I can draw the schematic, I have to first make symbols in KiCad.  The LM3909 is obsolete, and the TTL 7473 has been replaced by updates to other technologies (LS and HCT).  Neither part is in the standard KiCad libraries.

Here are the symbols I drew up:

The 7473 has two flip-flops, unit A and B.  The symbol has a third unit just for the power connections.

While perusing the datasheets to make the symbols, I discovered that the circuit my dad created way back then abuses the IC rather more than I thought.  I'll explain all of the abuses in a later log post.