What kind of modifications are needed to make my model a seat go all the way back and get rid of the package tray, so the seat rests up against the rear of the car.
I just did this on my coupe, Van seat. I spent about an hour using heavy duty zip ties and compressed the stock bottom springs to make the seat more shallow, it just doesn't work real well. I am 6 foot tall and with a four inch chop I NEEDED a thinner seat. Same goes for the back of the seat. Trimming the rear tray is almost self explanatory, just take off a little at a time to fit properly.
Don't know if your are stuck on using the stock seat or not, but I do know this is the only way for me. In my Tudor I have early beetle seats in it, it is not chopped though.
You can see in the pics where the seat base is riveted to the floor. Grind off heads and slide the whole thing back. Where it lands on the floor could be a problem. The body bolt is there. Drill some holes to remount. I'm thinking the front holes won't be in the subframe anymore. No problems that you can't fix.