Seat back Bolt to seat fram bolt ..... Missing? Where can I get one?

[chaps70rt]

I am in need of one of the bolts that hold the back of the seat arm onto the base seat.   The frame track has the welded bolt inside, but some clown put a smaller nut and bolt through and it is sloppy (obviously).    I am sure that Mopar must have used the same bolts for most cars.   If not, mine is a 1970 Challenger and the bolt missing is on the driver door side.   

Perhaps someone has an old wrecked seat that they could remove one of these bolts off of?? 

Thanks ..... CHAPS70RT