DIY Manual to Building a Cloud Chamber (2020) [pdf]
scoollab.web.cern.ch
scoollab.web.cern.ch
I tried using a plastic tub on top of the peltiers, but I think that was a bad idea, as the tub probably acted as an insulator as I didn't get the tub cold enough iirc (or maybe the plastic was just too thick too).
(Although the peltiers themselves had ice around them)
https://www.instructables.com/Make-a-Cloud-Chamber-using-Pel... is one that looks good.