I need to issue a disclaimer in that I do not own a canned ham but I have been researching dinette/booth/banquette design for a possible cargo trailer conversion.
Here is a link with dimensions and construction details for a dinette constructed as part of an Airstream remodel:
http://vintageairstream.com/cabinets-dinette/.
I also found and saved this drawing with dimensions for a restaurant booth:

You'll see that the dimensions in the drawing and the dimensions for the Airstream are almost Identical. It's mentioned in the Airstream remodel, but I think it is important to point out, that you need to consider the
compressed cushion depth and subtract this depth from the seat height and seat depth. Also, for comfort, it seems that it is important for the seat back angle to be not perpendicular to the seat base but to be tilted back 5-10 degrees from vertical and that there is overhang of your seat cushion beyond the front of the seat base and/or to angle the seat front back.
I'm at work now, but I think I have some more info at home. Let me see what I can find.