I am making a cabinet door. I cut 4 pieces of 1x3 and routed a 1/4" grove
in them to take a plywood panel. I then routed a 1/4" tongue on the ends of
the short pieces to mate with the grove in the long pieces.

I "intended" on assembling the door and then routing a 1/2" roundover on the
inside and outside edges of the 1x3. I made up a partial sample, and like
how it looks; simple but strong.

Well, it just occurred to me that panel will get in the way of the router
bit and prevent me from doing the inside roundover. And I can't do them
before assembly because they won't fit together properly. And I can't do a
temporary assembly because it will be too flimsy to hold together properly
without glue.

I know there are special router bits for this purpose, but I have already
cut the panel grove, so I am kinda committed.

Any suggestions how to make this work?
In the end I expect I will have to assemble it temporarily and hope for the
best, but hopefully someone will have a better idea.
thanks