Yes, the old model action parts can be installed in a new model Bearcat.
The bearcat NM frames were not machined differently for the NM transfer bar. They just use the OM retrofit transfer bar conversion parts.
As Bear Paw Jack posted, the NM frames were made longer for a longer cyl when the 22 Mag was introduced (and failed). So the only different part is the cyl pin of the NM, it's a bit longer. But you can still use the NM pin with the old actions parts. Or the OM cyl pin will still work as well, a bit shorter but not too short to work.