As mentioned, barring a really good and non-obvious reason to retain your current square-taper bottom bracket bearings, I'd suggest spending $20 on a new Shimano BBR-60 bearing assembly and then installing a Shimano GRX crank set, which is available in 48/31 with 172.5 arms.

There might be some concern over your derailleur's ability to shift a 17 tooth gap. In my experience, Shimano derailleurs that are spec'd for 16t, shift 17t just fine. Not sure about other brands. If you really require a 32t ring, at least one manufacturer sells one for GRX cranks, which could be swapped in.

Or you could install MegaExo bearings and an FSA crankset that is available in 48/32 with 172.5 arms, to save a few bucks by using lower-quality parts.