Welcome to the site...
The HiPo C5OF-12127-E dual point distributors were made in fairly large numbers and were a very popular over the counter ignition upgrade back in the day. The earliest units were cast with the FoMoCo marking, and these were phased out around 1967 by units marked AUTOLITE. The AUTOLITE casting gave way to the final version marked Motorcraft which came along near the end of 1971. Service replacement C5OF-E dual point distributors were produced well after the 289 production was replaced by the 302...
Based on the date code, yours is a service replacement part, and would not be correct for a "numbers matching" application. Values vary depending on condition, and range from around $100 to several hundred dollars. While all 3 versions are functionally identical, almost all original factory HiPo 289 engines came with distributors stamped FoMoCo, until 1967, when the Autolite castings were phased in.
Since your heads do not have the cast in spring retainers, they are not HiPo heads (which have a C5OE-A or C7ZE-A casting number). Early HiPo heads used with 5 bolt blocks will have either a C3OE-E or C3OE-F casting number. All 6 bolt 289 engines use the same block casting, but the HiPo blocks were only cast at the Cleveland Foundry, so the casting number should be C5AE-E. Windsor Foundry 289 blocks have a C6AE-C casting number, and were not used to make the K Code engines.