Would anybody here know the diameter of the lenses for the Adlake marker lamps applied to the Norther Pacific S-4 class 4-6-0s, as rebuilt in the late 1940's (when the large engine number boards were added). Asking be cause I am not entirely sure of the size, but have found some lenses and would consider purchasing them to help with the cosmetic restoration of NP 1356 in Missoula, Montana. The idea is to have the headlight and markers lit, but need marker lenses to replace those missing.

Any assistance is much appreciated.

Michael Seitz
Missoula, Montana