Denny,
If you are looking at the 1947-55 Factory Assembly Manual, Section 10; Sheet 3, that is a drawing for a 54/55 bed.
1953 was the first year for a side-mount tire carrier on a 1/2 ton truck and I think that 1953 was also the first year for larger pickup trucks (if I am wrong, someone will correct me).
You did ask for a picture "for an original factory side mount for a '50 3600". Most likely you have already searched the 1953 long-bed pickups in the gallery and there are no side-mounts. So, a picture from an earlier truck fitted with a non-factory side carrier would be helpful to you.
Tim
