On those older models, a clutch master cylinder leak will run down into the fuse panel and smoke pretty much everything.
Go with what cruiser said, replacing the panel is a chore but doesn't require any special skills or tools (been there done that) just time and maybe some yoga skills.
Do yourself a favor and pull the drivers seat, you'll be under there for a while.

Definitely replace the hydraulic line with the master and slave cylinders.

The fuel gauge float is a hunk of foam, no way it leaked. Your problem is related to the panel issue.

 

I sent you a PM.

 

Know where I can get a new or good one if I need to? And I replaced the master today doing the slave tomorrow. What hydraulic line ? The hard line?

 

The line is steel with a flexible hose crimped on it.

 

Here is a photo of the fuse box terminal removed. Super easy to do.