It has come to light that CBS ordered, and took delivery of, the GE 4-V's for their New York Broadcast Center (and WCBS-TV local operations) and Hollywood Television City in 1965, the first delivered around April and the last some time in the summer, and would thus have been fully equipped by the time the 1965-66 season came around; this from the April 26, 1965 issue of Broadcasting magazine:
https://www.worldradiohistory.com/hd...-Page-0052.pdf
Thus the first CBS film chains would have actually been PE-24. I wonder, given the variant models as PE-24A and PE-24B, which of those two would have had the rounded edges on the camera head, and which would have had them square. I know CBS went with the round-edged variety.
Apparently, another set of GE chains arrived the next year (the earliest references to PE-240 in GE advertising was March of 1966), as much of the photos taken in CBS's telecine department had the appearance of 240's.