Website for obscure brass for reloading

[Drydock]

https://www.ammunitionartifacts.com/

[Sir Charles deMouton-Black]

For reference purposes another good site is "Old Ammo"

https://www.oldammo.com/

For tables of dimensions usable for cartridge case conversions look here. Go to the bottom to navigate to other types of ammo; Note that it does not list rim thickness.

http://cartridge-corner.com/revolver.htm