Yeah I doubt Mike has a bunch of 712 lifters lying around but you never know.
You might call Jeff at C Rums and ask about getting yours welded. Turn around time maybe a few weeks. Last time I sent a Benelli lifer he had the welded ones in stock and just sent a finished part back right away but with the 712 you may have to wait your turn.
Might be better to buy another lifter to send off so your not without a gun for awhile.