1940 ford coupe seat bolt hole dimensions

[geoford41]

I have a 1940 ford Standard coupe front seat and need the dimensions for stock mounting holes for a split back seat. The floor is an aftermarket Bitchen floor so there is no stock floor reiforcement to reference off. I am fabricating 1/8" by 2 1/2" wide X 24" long flat stock to go in place of the stock under floor reinforcemnts but need the dimension from the toe board to the front hole on the seat or from so other reference point such as from the "A" pillers back to the front hole. Any help will be appreciated