
Welp, answered my own Q about an hour after posting this...It turns out the metallicy looking stuff is thermal compound. A little removal of that spray on insulation stuff and I found I was able to remove the peltier with the aid of a knife.

A quick test since the peltier isnt fully "potted". Yep, hot on the heatsink side, cold on the other.

Unfortunately, my C-clamp managed to do this.

The smallest one is apparently very well epoxied to its heatsink as when I tried to slip a knife under it,all i did was crack the ceramic. O well, itll make a good demonstration piece.
My next Q: how should I pot a pelt, can I just smear thermal white goop stuff up into it to seal it well?