Touring Body Metal Question

[JRSpada4]

I recently decided to remove the windshield on my August 1924 Touring to tend to some rust and replace the rubber bits. As part of this, I will need to paint the cowl as well. I figured, removing the cowl should make the process of masking easier by eliminating it. Boy was I in for a surprise. Once I got a closer look, the top rail that goes from the vertical pillars to the top of the firewall area are completely rotten and will need to be replaced. I think I've got a good idea of how they are installed and a possible game plan to get to them. I think the approach would be to remove the firewall to get at the front of the body and then remove the nails in the body panels, peel the body panels back and remove the cowl. It doesn't appear that the cowl is riveted to the front of the body at all, but is riveted to the brackets near the instrument panel. My question is this... is there enough flex in the body sheet metal that i could remove the nails holding it to the wood and pull it back enough to be able to get to just those top rails and their fasteners? Has anyone tried this? The rest of the body seems solid and is in good enough shape that I don't want to lift the body from the frame unless it is absolutely necessary.

Edit: yeah, so scratch that idea. I completely forgot how the firewall attached to the brackets. I’m going to have to pull the fenders and then slide the body back just enough to get the firewall to bracket bolts out. Now to source some wood and clean off the bandsaw

[Will_Vanderburg]

The cowl is riveted in that area but I don’t recall how. I know it’s riveted to a metal bracket that is attached to the top drivers side false door wood. I cannot remember on the passenger side.