I should find my schematics-- When I was younger straight out of college I designed a digital clock that was relay-based. I made a 0-16 counter circuit on one

I should find my schematics-- When I was younger straight out of college I designed a digital clock that was relay-based. I made a 0-16 counter circuit on one board and a 10-reset circuit on another board. I didn't have 4 pole relays, just 2 pole, but I did try to make use of a mix of normally open (N.O.) and normally closed (N.C.) to keep the parts count low. The binary-to-7 segment logic was to be implemented using a diode ROM. I had the same idea about using clear relays--so you could see the parts working, but I couldn't find those at the local electrics shop, so I instead just took the plastic housings off of standard relays.