Out of curiosity, I looked at a few ovens where specification sheets are available.
Depth/Height from cooking surface to bottom of oven:
13.77" Mario Acunto, Classical Series. What Craig has in his garage.
13.50" Stefano Ferrara, M120 through M140 ovens
11.50" Woodstone, Mt. Baker & Mt. Rainer ovens
9.00" Gianni Acunto, Models 4 through 5 1/2 Palms
7.00" Marra Forni, Napoli Series Model 150
6.75" Earth Stone, Model 130-PA
6.00" Valoriani, Mugniani series
6.00" Forno Bravo, Napoli series, Modena 2G series, Professionale 110 oven
EDIT: The Ferrara ovens have gone through some changes recently. The shape of the exterior of the oven is clearly different and can be seen when looking at the oven at Paulie Gee's in Greenpoint and the ovens I have being shipped to me (with the Greenpoint model being more rounded above the entrance to the refractory chamber). The shelves are also different, with the tubular supports and circular platters to hold plates being replaced by a more streamlined shelf.
The oven at Pizzeria Bruno is the older model. I am not certain if the depth of the floor has been increased in the newer Ferarra models.....if it has then that may be why Omid thought he saw a noticeable difference in floor depth between Craig's oven and the (older) Ferrara model at Bruno,
This ignores the materials used to make up the cooking surface or biscotto and what is used for the insular materials below the cooking surface, which are of course vital factors as well. --K