Is this a case where you already have the stock that has a Remmy 700 inlet? Manners tailors each one of their inlets for "700 footprint" actions to the specifics of said action. Axiom, Impact, Tenacity, TL3, etc. The main differences being straight vs swept bolt handle and ejection port shape. The fit in the chassis part will be fine, except for a few very early Curtis actions that had the recoil lug in the wrong spot.
As far as the magazine interference issue, Curtis uses a .750" bolt, vs a standard .700. You are likely to have feed lip interference no matter what chassis or DBM you use.
Also, if you send your stock back to Manners, they can rework the inlet for you to fit the action of your choice.