Analog Combo - Leica CL, Industar 50, Eastman Double X, HC-110 Dilution H.

Lytkarino Optical Glass Plant, No. 233 — Lytkarino. LZOS -1953 era

https://en.wikipedia.org/wiki/Lytkarino_Optical_Glass_Plant

Double X:

https://podcasts.apple.com/us/podcast/bringing-it-all-back-home/id1471887835?i=1000522462861