With the D5, the use of the 150mm requires one to remove the top condensor lens completely, and if I remember correctly, a piece of heat-absorbing glass is recommended. I have used the 135mm for 4x5 (for 16x20 prints) -- perhaps for 100s of different negatives over the years (but it has been 20+ years since I have done any serious amount of silver gelatin printing). It was fine, though I always ended up doing a bit of corner-burning...but may have done it with a 150mm lens anyway.

We have the D5-XLs, which might have had a taller column than your old school's.

I have recommended using a 135mm lens to students for very small prints from 35mm many times. Seeing them carrying in a box to put their easel on is a good clue!