as they are bolts and both are 1 inch long with the same head do you care?
provided they have the same head, and it looks like they do.
obvioulsy the correct bolt will be better from a fitmnet point of view BUT if i had 7/16 holes i'd still buy the 3/8 bolts
as that gives more wriggle room for getting the bumper nicely aligned. If things are a little bit "on the wonk" i'd rather have the wriggle room and invest in a washer than have to oval the holes in the car or bracket
obvioulsy if these go into a captive nut then you need the right size, but they have nuts so i guess not.
If they are just through bolts and the size will be invisible to all but a chap with a keen eye lying under the car well.....
i'd guess one set is for earlier bumpers with less weight than the other set, its a 1970s car they probably made the bumpers springy or have collapsible mounts or some such, adding an extra couple of cantilevered lbs for safety in 4mph crashes . hence fatter bolts for some,
As usual just a guess...
some will say get correct bolts for age of car i am not that person...
Hang on
if the spares you have don't fit they must be 7/16 i.e 3.5/8ths and your car is 3/8
or is it the head or length thats wrong? or just the wrong nuts?
Dave
