Bare metal spots after blocking-What next?

[Chad1376]

Hi all

I'm block sanding the bed of my '51 International L110 and have sanded through primer to bare metal in a few spots. I'm not sure what type of primer I should use from this point

So far, I've got Nason 491 Etching Primer over bare metal on the bottom. Over this I have Nason 421-2k Primer and some epoxy glazing filler.

Everything is smooth and straight now, but what comes next? Can I use sealer over both the 2K and metal spots and move on, or should I hit it with something else first?

Thanks for any suggestions.