The attached picture is of my original 1968 manual drum brakes master cylinder casting number 5452310, application code BS. The date code is C8 8 (March 8, 1968).
The foundry code is T37. My car is an 04A Norwood car. Every master cylinder date code I've seen so far has been in the Julian form. Did the two date code formats co-exist or did one supersede the other?