1940's Chrono Tachymeter Keeper Configuration

I'm having a strap made for our tachymeter believed to be 1946 vintage and having trouble finding details of the correct keepers for the strap maker, can anyone help? There are so many variations out there; single wide keeper loose or sewn in, two narrower keepers either one or both sewn in and then aspects like does the material fold around at the edges and are there stitches or pressed lines and how far in from the edges? I found one magazine ad from that period showing a single wide keeper but that was of a lower model Omega and I've heard that the higher end watches would have had two keepers to avoid the loose strap from flopping around. Does anyone have a strap from one of these from back in that period they can post photos of or any other leads or info that can help?