Looks great Graham.
I think there was there a photo of that barn in a past issue of Wargames Illustrated. It looked brilliant, however all of Herb Gundt's work does.
I'll be watching this with interest. I have wanted to build a barn like this myself for some time myself, but in 15mm for my Brother Against Brother games. I have the model from Monday Knight Productions (the old Scenic Effects models), which is nice, but the roof isn't removable.
Cheers,
Barry