I have been trolling around for a few years getting lots of insight for my '74 Outlaw-ish build. Thank you all.
I Could use some advice on rust at the gas pedal support under the car. The floor pan was rusty (see pic) but had no holes so I used Corotech Rust Arrestor and have applied 1 of two coats of Eastwood Encapsulator. The support under the car creates a hollow space which is showing rust leaching from the sides of the support. I think I have two options and would like some thoughts on them and any others you could think of.
1. Remove the old support, treat the bottom of the pan and install a new one. My biggest issue with this is that it couldn't be in a worse location (working with jacks and stands)
2. Drill some holes in the sides of the support and use the interior frame encapsulator, treat the outsided and hope for the best.
Thanks for any input you may have
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How much section loss has occurred? It looks minimal

I always drill a drain hole in that pedal depression area....
wet shoes always leave a small puddle in that area.
you can pour a couple of ounces of water in the area and see right where the drain needs to be.

Doesn't look too bad. Best plan is always to try and remove all of the rust to see how bad or good things really are before painting over it. Hopefully you did that before using the 'encapsulator' proroduct. Definitely do that before treating the underside.

If not opening up the inner cavity (I wouldn't unless you find holes after grinding the rust away) I'd do as Brant suggested and then spray some Ospho in there.

Pan was not flaking and did not punch through when stabbing it with a screwdriver.

I removed all loose rust with a wire brush on a grinder which did not uncover any holes, then used the rust arrestor. After rinsing off with Water and Baking Soda so stop the Phosphoric Acid reaction. I sprayed with the encapsulator for a little extra protection.
I think I will try to clean out the cavity underneath the best I can then hit it with the interior frame encapsulator.

Mine was the same with only minor pitting PO had treated it with red oxide zinc primer,because of this primer I used POR 15 silver over top and it came out great...and still is after 4yrs,you have done the right thing ,cheers.

Remove the rust with Ospro, and fill the pin holes with JB Weld. then coat with rust encapsulator and POR 15

Ospho is the brand. Used it a number of times, works very well.

Yes, but must rinse thoroughly prior to coating with primer.