Have you tried calling Gregory Poole for the mounts, they would be the CAT dealer that installed or speced the motors for Hatteras? Seems like ACY just couldn't locate any or something along those lines.
I just went through a similar ordeal. My job was subbed out to Seaworthy Marine out of Palm Beach and I couldn’t be more satisfied. They did a laser alignment and found a strut out and also had to replace a couple of motor mounts. I to was told of difficulty locating the correct mount (Mans). If you have trouble recommend ACY look at AV Products out of GA. They make all sorts of marine engine mounts. There is a durumeter (???) number for the density (???) of the rubber so be aware of that. I had no idea that motor mounts had so many variables. My work was done just down the river from you at River Forest Yachting Center. I would be interested in how you like ACY. BTW love your new boat
At this point, my mechanic in Va, who was the head mechanic at Carter CAT, said he can get them. ACY has put the boat back together for now, will change them once the boat is back up here.
ACY has been Great! They seem thorough and respond reasonably well to calls and questions I have. My mechanic says isoflex has the mounts. I am waiting to talk to the head mechanic at ACY to find out more of what the issue finding them was.