Hi Gary
I had Greg King owner of Kenyon Machine shop here below my house in San Diego
custom make a mold and then pour me a number of 1" x 1/2" round travelers( original ones were pop metal that all crumbled so Greg mixed a harder matl looks like Alum ) under the seat that has a 1/4" very course wide tread screw shaft that screws threw it with a nub on each side that holds it in the Durant steel mech to pull the seat forward and back right in the middle almost on the floor under the front seats of most 30 & 31 Durant cars that worked real slick, using the Durant factory stock wide thread shaft very well made shaft ( can use factory one over) , that had a short ratchet handle hanging down to move the seat fore & aft. As a long time clubber and helping me a bunch you can have a extra one of these that I have here in stock. I can cell phone u a picture of it if you like.
Faithfully
Lance Haynes
San Diego, CA
Where Are You From? San Diego, CA
Do You own a car built by Durant? Yes a number of them
Sorry just saw your post. i have some '31 model 619 parts stored away but its too cold to even look now. contact me later this winter if you're not in a rush.