The email issued mentioned earlier this week is now fixed! You may also have received previous emails that were meant to be sent over the last few days - apologies, this was a one time issue and shouldn't happen again!
I think the piston mount you have is a Bravo. Pretty sure the 46M uses a Charlie piston mount. The Charlies are tapered on the body instead of the straight threading on the (Bravo) one you are holding.
I think the Hybrid 46 is a Bravo pattern, but the Hybrid 46M is Charlie pattern mount.