"Lew Hodgett" wrote in news:54b1b26f$0$42944
:

The use of 3/4" ply panels turns the 2" poplar into little
more than edge banding, so having the ply and poplar the
same thickness has some merit, especially when mounting
hinges which allows 2" wide rather than 2-1/4" wide stock.

Using rail and stile construction eliminates mitered corners.

The ply panels are glued into the poplar frame.

Since the poplar serves as edge banding, think of the door
as a top that is mounted vertically.

Ah, I see what you're thinking. I think, if I wasn't going
to float the panel, I would simply edge-band it with poplar
(or whatever hardwood was handy, since it'll be painted),
thick enough to hold the hinge screws but no more. I would
miter it, altho as you say since the banding isn't structural
it could just be butted.

Well, stryped should certainly have plenty of different ideas
on how to solve his problem now :-)

John