Partly depends on whether the triple is 52/42/30 or 52/39/30. These require slightly different FDs because the
one that works for a 39t mid CW has a deeper vertical cage in the back than for the 42t mid so the cage when
set for the 52 (or 50) will hang up on the 42 where it clears the 39t. If you look at pix of prior era FDs for triples
you will see some of them have larger vertical cages than others. The 4503 will have been meant for the 39t mid
option. A friend who liked 44t mid rings dremeled off 3-4mm of the bottom of the cage and made it work about
10-12 yrs ago. I would not be concerned over the 52 vs 50t large CW. FD won't care much.