Old battery well rust, 911

[Hotshot]

Question about battery comp rust.

Along my 911 search I came across a nice 86. It’s a drivers car, normal wear and some dings. Overall like a 6-7 / 10 car. A lot of good mechanical upgrades to the car.

Only issue I have is one thumbnail size rust bubble along a window sill under the paint and this pic of some old rust by the battery compartment.

Owner says he oils it since he got it and it’s never spread.. I wasn’t able to hoist the car, just looking at it on ground. Are these localized if treated? The rest of the front drunk was clean.

[High Life]

That is a common sport for rust.

Its hard to know the extent of the damage without out removing fender and or front bumper. Granted it doesn't look too bad - but the bottom pan and front brace for the pan could be rotting from the inside..

Look at the front shock mounts and look for rust up and around the gas tank

Here's a thread (of a much worse issue) that has pics of the front corner where the battery sits for reference. The rust was coming from the front shock strut mount and rotting through the corner.

Talk me through rust repair....Please