Really need some help here guys. I have an 81 300D and would hate more than anything to see it go, but just recently I noticed rust on the floorboards by the outside back corner of both front seats. Hopefully the pictures I'm attaching show up. I'm just hoping for your guys' advice on whether this is a repair I can manage myself(I'm not a welder), or if I can't, how expensive of a fix am I looking at? I know that it's rusting in probably the worst possible place. Thanks for any help.

First two pictures should be view from inside the car behind the driver seat, you can see the road through the floorboards here. Last picture is from the bottom of the car.

I know it's in bad shape but the engine runs beautifully so I'm really hoping this doesn't put the car at junkyard status here.

Attached Thumbnails