Getting an 80 standard seat to fit on an 80 special

[justinc1081]

Bought a standard seat on eBay, getting it to fit on my special bike has so far resulted in me cutting the back 3 inches off the seat pan and ready for another go with the cutoff wheel.
Anyone else ever put a standard seat on a special frame (1980) and care to provide some tips

Started with

Foam of what i want it to look like

And after first round cut

[justinc1081]

Little more cutting

after some more cutting and grinding ive managed to make it fit proper - still need to get some taller feet for the back 2 rubbers. Sanded the minor rust and primed/painted. Ready for foam again