Hope that the original poster has a San Jose car also - if no please provide your plant and we'll try and post some of those also
Car was built on the 12th jan 67 - San Jose
So somewhere in the 7R161xxx-172xxx range
The idea was not to have it be seen but as mentioned sometimes the stuff got loose and ended up not exactly in the place the worker had planned. Since it was not visible from the outside or in the interior inspectors normally didn't mind. IF you end up with a restored car with little showing the detail can be missed by judges and you'll loose points unless you point it out to them BEFORE judging starts. In these cases you should have made it visible in the wheelwells where the fender bolt nuts (J nuts) and the openings are or just leave a very small amount visible so they don't miss it. JMHO
As a note - at 50 years the caulk on many cars has turned to dust, gotten hard as a rock, cracked and fallen out on many cars. What remains is over a dusty light gray unlike what it started out as due to the elements and exposure. So don't get mislead and use that ugly light gray stuff that you can buy from some vendors or in the 80's packaging NOS boxes
In these two first pictures a small 1/8" bead of the product was created ad they tightened the fender into place. Since the contrast is low I highlighted the edge of the fender and pointed out the caulking
A nice original car - Passenger side was done pretty neatly with no exposed while on the diver's side it appears that the caulking fell off the fender as it was moved into place and the original width and size is visible as it clearly missed it's mark
Hope this helps. If not I'm sure I have more