Not really, the FAA considers this a Continental C-125, no matter what has been done to it.
the problem is, it is in a C-170, that is now considered un-airworthy for having the wrong engine installed.
The FAA does not know the engine has been altered. No paper work no alteration. They would have no reason to look, no accident, no paper, the FAA is but uninformed.
After a plan formed by me and my PMI, the owner will request a letter of authorization from the FAA to replace a missing data tag, for the original C-145/0-300-A that was delivered in the 170 from the factory. We know that data tag was destroyed.
But next question.
All maintenance records from 1960 to date were recorded on the C-125 S/N, now we will have a data tag showing a new/old S/N how do you cope with that?