[Excelsior]

If the seat does not move under force, is it fixable?

Is there a seat I can use from another vehicle that would be better?

 

[chuckspeed]

The seats aren't normal seats...

The seats are affixed by a pivot/slide arrangement - the front pivots, the rear slides. The ratchet mechanism is on the outboard rear of the seat; the pawl is inboard of the slide.

It's unusual for the pawl to be hanging up; what is more common is the front pivots rust into immobilization. Pull up the front carpets where the seat posts meet the floor; spray some penetrating oil there. After letting them sit overnight, some rocking back and forth in the seat may work it loose.

Be advised this area of the floorpan is a weak spot on Mantas/Asconas - I've had Mantas where the front pivot area rotted so bad the seat posts dropped thru the floorpan! This may be the case here - hard to move seats are a sign rust has been at work on the floor.

 

[GoinManta]

Mantas are easier to find replacement seats for than the GT. I have used a set of 91' Toyota Celica GT seats. If its a driver and not a stock restoartion I HIGHLY recommend replacing the seats.