Bench Seat support fixes

What's the issue, specifically? Foam crushed? Seat back too far forward or back?
Was the previous owner pretty heavy?

I've had luck putting spacers under the front or rear of the seat, or both, or sometimes just under one corner. But that just changes position, not fit, and helps knees and steering wheel reach.

Also, what's the rake on the car?

No support,... it's like sitting on a toilet seat you sink down.