Replace this tank?

[clesch]

I’m currently fixing the mechanics of my car and sent of the throttle bodies to Alan for a rebuild as well as the MFI pump to a local Bosch specialist.

I used this opportunity to take care a tiny rust spot near the tank and decided to drain and remove the tank for this because I also have some accuracy issues with the fuel gauge sender.

So held my phone into the sender hole and made a video of it!



The (original) tank is clearly dirty. I wonder how much of it is rust and how much is other gunk that could be cleaned out.
Or should I replace it out right away? Believe it or not, the car ran fine last year.
Fuel filter will be replaced of course.

[classic]

Looks like mostly varnish to me, if you are worried about it you can get it professionally cleaned.