1959 1960 Mercury crossover parts

[Stephenorf]

I have a 1959 Mercury Monterey and I'm trying to get the windshield wipers operational. The car did not come with a windshield wiper motor, so I purchased an aftermarket electric replacement from New Port Engineering. The problem is that the "Windshield Wiper Auxiliary Drive" will not lay flush against the firewall while orientated in the correct mounting position. When I got the car it was loosely bolted to the car with the bolts being partially cross threaded in.



I noticed the engineering number on the "Windshield Wiper Auxiliary Drive" is C0MB-17579....which seems like it was made for 1960.



I know there were a lot of major styling changes from 1959 to 1960, but I was wondering if the "Windshield Wiper Auxiliary Drive" for the 1960 Merc should work in a 1959 car. Many times the parts are interchangeable across years. I checked out the Merc catalogue and the part numbers are not the same:

PD9M-17579 for 1959



And C0MB-17579 for 1960



So the prefix changed from PB9M to C0MB....but did the actual part change enough to where they are not interchangeable?