Well the 46 is definitely not for sale, that would probably get me divorced, the originality and the solidity of the car makes me question the hemi swap, but if I was to swap nothing says hot rod like a hemi.
which brings me to the next question of a p15 since I have no experience with a car this old is the engine at 95 hp capable of being driven or for parade duty only.
I have tried to sell the imperial on a hemi based website as a restorable car with no takers ( kind of felt bad after guy I bought it from gave me the original bill of sale with the matching engine number on it), it is a 331 ive checked the casting numbers and it does not have the extended bell housing. I also have the original bill of sale for that car for 1953 ( cost $5K!!). So if someone was interested I wouldn't be completely apposed. ( 331 engine does run a little with gas in carb guy had driven it around yard the day before I bought it)
original bill of sale
picture of 54 I would say late 80's early 90's judging by the style of printed picture