Thanks, I found a 4015C. Looks like the date code is 10B. What date is that?
Should be two or 3 digits, first one or two are the week, last is the year.
Below are the same distributors. Top is what came in the car, built the 7th week of 1970. The second it a service replacement, built the 38th week of 1976. Note the 4018B"S" and the Chrysler part number change on the second one.