My three Omega collection.
21st birthday present Speedmaster 321
60th birthday present Seamaster Aqua Terra
Speedmaster trilogy issue which I actually bought myself!
Another Tissot trio: cal. CH27; cal.786 automatic; and, the last with the Astrolon "Systal" (Systeme Tissot d'Auto-lubrification) self-lubricating plastic movement.
A while back I realized that I had a couple of my very own Trilogies: Speedmaster, Diver, Railmaster. If we allow an Aquaterra to stand in for the Railmaster -- which is reasonable since the Aquaterra was meant to be a modern successor to the Railmaster, this is what I've got.