It is possible that it finally left the factory in 73, even with the old style tuners. Typically the end run EB-2s have the later Schallers, but I have seen way too many Gibson basses with seriously out of date parts mix ups, like bar bridges on models that should have evertilts, late 50s basses with 60s chrome parts, and solid headstocks on what would appear to have been a slot heat era, etc. I have always suspected Gibson would throw screw ups and slow orders into a get to it later pile.
oh yeah, I was going to talk about that.... note also the raised position of the crown inlay - which stopped in late '63/early '64.
Also no 'made in USA' - which i'd expect on a 1973-made neck.
The serial number seems to be 128979. Which is 1963
and 70-75.
So I think this is an old neck. Necks were stamped with consecutive serial number before they were attached to guitars back then. So this neck may have sat on the 'pile' for 10 years, already numbered, just waiting for the day they needed one. If this were the case, and it was entered in Gibsons leger as a 1973 shipment, it might explain why some of these numbers were used twice... they may not have been, just odd serial numbers shipped wildly out of sync.
Alternately, someone may have just stuck an old neck on a newer body, but if so, it was done pretty seemlessly.
Another interesting example for sure
On balance i'm undecided about the gold, but if it is a 1973, which is plausable, it would have to have been special ordered anyway, even with chrome hardware.