Filling holes in hull

My boat, Lowe 20', has lots of holes that has been drilled in the hull. The previous owner added lots and lots of stuff. Just drilled a hole and screwed/bolted whatever. I bet that there is 35/50 holes. What is the best way to fix/fill them? I ordered a tube of JB Marine Weld and thought about that - also body putty - aluminum rivits - or or or?

Help sure would be appreciated. I am going to use a Styx Stencil kit outside and inside and hopefully this will cover most of the fixes.

Thanx

rrawhide


ps: the console looks like it has been shot with a 12 gauge!!! not really, but he must have had everything known to man bolted on that thing!!!!!!

Aluminum closed end rivets and 3M 5200. This is the easiest, fastest, and cheapest way and it's permanent.
Find the biggest hole up to 1/4 inch, order that size rivet and drill the rest to that size.

Agreed for the below water line holes, but above you will be fine with just 5200...works for lots of us.

I just finished fillin a lot of holes in my own, I sanded the heck out of the areas around the holes on both sides and then packed them with the JB marine. Let it cure for about a week and the used the dremel to clean up the excess. After a quick mist of paint, can't tell they were there at all.