Fender 70s bass finishes



Does anyone know if Fender in the 70s used a red undercoat  / primer on certain finishes  ? I have a black 77 fender bass which in places has what looks like red underneath in places  -  the previous owner told me that he bought it from new and has not been refinished .. 


I have seen a couple of other examples online but nothing 100% ..


https://ibb.co/ZN7DfyH
https://ibb.co/n05tyc8

Comments
ICBM Frets: 75721
30 Oct, 2024
Could be a factory repaint - reportedly they did put black over faulty other colours, the most likely candidate would be 3-tone sunburst which has red as the first coat around the edges.
ICBM said:
Could be a factory repaint - reportedly they did put black over faulty other colours, the most likely candidate would be 3-tone sunburst which has red as the first coat around the edges.
That looks very much like the edge of a factory 'blown over' sunburst to me too. as @ICBM says - if they borked up a sunburst in the factory they often used to just blow it over black and call it good - sometimes without even a clear coat over the black!   
Funkfingers Frets: 15568
30 Oct, 2024
ICBM said:
the most likely candidate would be 3-tone sunburst which has red as the first coat around the edges.
My 1978/79 factory fretless P Bass exhibits the sandwich of finish coats to which @ICBM alludes. Yellowed clear base, transparent red, slightly brownish black, yellowed clear top coats.

The clownburst red pigment fades differentially in strong sunlight - to the extent that, for a few years, my bass resembled my bandmate's 1977 tobacco sunburst Stratocaster. Eventually, the amber colour on front of the Stratocaster also faded, leaving it looking like a piss poor attempt at a Fifties two-tone 'burst.

I agree that the black coat on the OP's bass is unusual in not having clear top coats.
Thanks for all the comments , the black finish does look a lot thinner than the other 70s basses I have owned in the past . 
You can check by removing the neck and taking a look in the pocket where it’s likely to be clearer.

Another giveaway is black pain inside the pickguard screw holes. Looks like yours is a factory finish.