FYI, I mounted a few of the FD's into this Record shishkabob of sorts on a wrecked tube as an easy comparison:
I'm missing two of the original Record variants technically. That said, I am also unsure if the 4-hole, early-'78 Super Record FD should be considered here either, for I've heard passing references that it was used in NR as well.
Nevertheless, the above is a pretty decent DIY spotter's guide - 1958-1966 (Record) at top, 1967-1972 second from top, 1973-1977 second from bottom, 1978-1986/7 at the bottom.
On a side note - I was rather surprised to see that the earlier Record body is noticeably bulkier:
-Kurt