For the four silver rings on the top front of the cuirass - there was a time that I could have sworn the recommended thing to use was something similar to these two Tandy clasps:
https://www.tandyleather.com/en/product/oval-spring-snaps-nickel-plate
https://www.tandyleather.com/en/product/round-trigger-snaps-nickel-plated
If you look at the close up of the cuirass, it does appears as though there is some metal extending from the silver rings, similar to how these Tandy clasps look, so I'm a little surprised to see that the CRL is just going with only "rings". Though, is that why it goes on to say "Clasps are acceptable, but rings are more accurate for attachment."? If rings are being considered more accurate though, then what is the explanation for what appears to be the metal extending from them?
-Gilles