Update 8

[jd2cyl1943]

Here are some pics of the seat platform. That's all I did was remove the platform.

 

[GermantownGreen]

Looks like some of our stuff. Rust worms
they call it. GG Wes

 

[Steve@Advance]

Do you have access to a welder, preferably a gas shield wire welder, (AKA a
MIG welder), and a 4 inch grinder?

Cut out the rusty part back to good metal, make a cardboard pattern to fit,
cut out a piece to weld back in. That nice thick seat will be good easy
practice!

Lots of how to videos on Youtube.

 

[caterpillar guy]

Lay a new plate the size you want to use on the old one. Drill the holes so they match and fit,then mark the size to be cut out, and weld the new plate in good to go.