Best way to deal with surface rust in the center tunnel? Options

[falcor75]

I have my '74 2.0 down to basically a bare shell (suspension is still in place) and I'm trying to figure out how to deal with the surface rust in the center tunnel.

A. Drill out all the spotwelds in the profile that holds the seat height adjusters and the tunnel itself and do it properly. Downside is that the flanges of the parts will be a bit mangled and might be hard to put back in place + very time consumning.

B. Cut open sections (on the top of) of both the profile and the tunnel, to get access and do the best job possible.

C. Using existing holes to scrape off lose rust and use a flexible arm with a rotating wire brush to get as much as possible out and then use long paint brushes to coat the entire tunnel with rust stopper.

D. Other suggestions?

I will run both fuel and brake lines under the car in the future and there is no rot to speak of, only surface rust + 40 years of dust.....