After all my musings, I decided I will be going with the Tank in steel bracelet... just deciding between the current Tank Must (Cartier just did a price increase!) or a pre owned Tank Solo (I like the brancards on the solo more)... after a chat with a Cartier SA, she advised the current Tank Musts have a propriety strap deployment and would be hard to use after market leather straps. However, a strap maker I contacted said he can still do custom straps for the Tank Must. The Panthere strap the Cartier SA said cannot be changed out to leather one.