It is good to fill the hole. First clean out any caulk,
corrosion, or antiseize, out of the holes. A gun cleaners wire brush, (22 size), is good for this. Wipe out the hole with Iso alcohol. Then mix up some WEST
epoxy with a dolop of white pigment... add enough silica filler to make it hang there, and put it in one of their syringes. Now squirt it around the edges, going around & around to the middle, and make a mound.
After a while it will be "green". This is when it is not liquid, harder than clay, but not totally hard yet. (30 min to 1 hr ??) At this point you take a
single edge razorblade, & slice off the part that stands high. Try not to concave it.
The white
epoxy "dots", will eventually turn yellow from UVs. If you want to touch them up to prevent this, you can avoid the
sanding by using
paint with an artist brush, right after you slice off the excess, for a chemical bond. (I'd use
hardware store, spray can, white appliance epoxy
paint.)
Get the stuff together, then it is a 1 hour job...
Mark