Everything you always wanted to know about the PT15 but were afraid to ask: https://www.mouser.com/datasheet/2/1...15-3105269.pdf

The N apparently indicates the rotor shape and orientation. (rectangular shape with rounded sides and a small triangular incision). It seems the R is not a viable alternative because of orientation.
The V means vertical pins
The addional numbers Vxx describe the configuration of the pinpositions:
V12 is comparable with V02 just slightly longer pins.
V15 means the backpin goes straight down instead of slightly bend inwards. You could probably bend this inward yourself.

The A means linear response

Considering the tolerances, PT15NV02-502A2020 might be a viable alternative as well.

From what little I learned in the past (way back when), you may have succes with trying contactspray first as already mentioned in this thread.

Mine is currently acting up as well, so I'm affraid I'm going to have to delve into this also.