Rear armrests in a 1949 Chrysler Windsor Coupe?

Before I tear out my back seat to remove the upholstered panels and see if there are armrest mounting bolt holes under there, does anyone have any experience with installing rear armrests in a '49 Chrysler Coupe?

I have some killer '49 Mopar rear armrests with integrated ashtrays, original coverings that match my upholstery with two bolt holes in the back of each, are the rear panels set up for these or am I going to have to rig it?

Thanks in advance.