Cab rust

[Angrywood]

Just like everyone at some point in time, i got some rust on the back corners of my 62 c10. I have the bed off right now after just replacing all the bed wood and want to get it back on relatively soon. I also know i should get this rust fixed before hand. I’m by no means a body shop guy or a welder. But i was thinking of just filling these small holes with a welder and then grinding it down flat. Will that work? I am more of a rat rod type so it does not have to be perfect. But at some point i might want to give it a nice paint job. Advice? Thanks