Thanks for your help on this. Those are fender bolts that are used but are longer.
The normal lower fender bolts are size m6 x 1 bolts about 1inch long. Original Toyota Part number is
90119-06394
However, the bolts needed for the mudflaps has to be longer as it goes through the mud flap AND attaches to through the lower fender.
I sourced some M6 x 1 bolts about 1.5 inches long with washers and they worked fine.
However, my original fender bolts were so rusted it out that they snapped when trying to remove them
So I had to drill them out and retap. What a pain that was.