Not sure about the Duvalls on the Model A's as far as the BopTop goes.

It should be able to work though.
I pulled the standard 32 top irons/oak bows for 2" chopped windshield off my 32 roadster and found it would be easily adaptable to my 31 on 32 rails roadster.
The only thing you have to do with it is to section 2" out of the front horizontal/longitudinal bar for it to work on the A.

It would probably work with the standard Model A windshield frame.
Not 100% sure there since I'm running chopped 2" windshield posts on standard 3-31 Model A stanchions.
A bolt-on swap for the most part - all that's required is grinding the stanchion so the post can go back and then welding the hole where you ground off the rear piece of the A stanchion.

30-31 A cockpit measurements are virtually the same as the 32.
The 28-29's are fairly close as well.
Only real difference between 31 and 32 is the 32 cockpit is 2" deeper.

It does look like the BopTop will keep the rain out fairly well when parked.
My stock style 32 top overhangs the side far enough that rain - and wash water - doesn't go inside.

My top folds, but even folded it sticks up a bit and for the runnng topless times I fold it, take it off and store it in the house.