I don't think little holes that are off the main load planes are a big deal. I tend to thing holes can be good for reducing corrosion. It is hard to totally seal stuff against water, and no holes means vapour is contained. But if one is completely sure no vestige of water can get in then that should be better. The insides of tubes like the stays and the blades shouldn't be heavily loaded. Sealing holes with braze or weld does not sound like a repair to me, grometing them with some metal would be better. I am assuming pretty small holes though, 1/4 is a big hole.