Thanks for the info. I was afraid of this. I sent an email to Customer Service about changing the MSH and installing an AMBI safety. They replied that after I provided them with the serial number they would sell me an AMBI safety. No mention of MSH nor impact to warranty. It looks like they have stopped doing custom work for a while. I may have to re-think buying a new pistol. Maybe I can find a used one set up the way I want.