Those 50's/60's and 70's Calatravas have a very special scent.
Going on that path is indeed a way to travel through many watches at an affordable budget, with many dial/case/hands combinations...
This is something I could go for as well.
I still remember your last "trio" post (with the 2509 if I remember well).
Can I ask you what is the "sigma" thing?
Congratulations for your new wonderful catch Joe.
Cheers, Mark