Removing front seats

The screws holding in the front seats are siezed and the heads are rounded. The steel underneath the seats is rusted. Will I need to cut out the seats? Will I need new seats do you think? Does anybody have any experience with stuff like this?

Well I have never seen bolted seats on a 81 Diesel or my 89-93 Cabriolets.

Pry the clips and remove the inner seat rail covers

One 8mm acorn nut and a allen 5mm IIRC then scoot

The Seat all the way back Holding the seat slid up and it will release out of the rails and car.

Granted I have never seen that level of Corrosion (ie:rust) on any of my Various Golfs/Cabriolets.

Here is how I dude it.
My Seat rocks and is hard to slide. - Topless Rabbit Forums

I do know that some aftermarket seat bolted to the Rails but they aren't OEM.

I don't think you have standard seats fitted in the car, look like someone has welded in some seat rails and not treated the burnt and bare metal and it's rusted.

Can you get a picture of the seats?

You may need to cut the seats out, repair the damage and start again…