vintage Hamiltons and Hamilton sellers, any suggestions?

It seems you already have found all the resources you need, especially the HamiltonChronicles are just immensely helpful when diving into vintage watches of that brand. Add the Gilbert to your list ;-)

Ebay and patience seems to be the way to go. You can still find a lot - really a lot - of replacement parts, movements, and yes, also crystals there as well (I use tiptopcrystals.com to verify the model number of the crystal I'm looking for, and there are still a lot of them floating around, even for the asymmetric watches). Sellers like "flashdealsallday" on eBay sometimes have movements that come with an original dial in good condition, in case you find a watch you like but the dial is not looking so good.

Prices for the solid gold models are through the roof, it seems. $3500 for a Wesley-B is ... quite a sum for about 14g of 14k gold. It IS a gorgeous watch, of course. But even sellers without such delusions of grandeur seem to be sitting over $1k these days.

Finally, to make matters worse (you're welcome!), I'd like to propose a Hamilton "his and hers" watch combo - don't know if your future wife would be into it, but it's a thought. And might make a difficult search even worse. There were several paired models in the 1950s, but the ones I like best are the Robert & Roberta - you can find the writeup on them here:
https://www.hamiltonchronicles.com/2015/12/1953-robert.html

Good hunting!