Interesting BTW The SPG on the gantry the reviewer refers to is almost certainly one of the US designs for a recoiless heavy gun based on the Davies recoiless principle with a counter weight fired to the rear. This is why a gantry was used to get the whole thing high enough to allow the rear facing barrel enough room when the contaption was elevated. I'm currently intermitently working on one of my drawings of the thing
I've just bought the "Book" - you can download it as a pdf for $2.99 via PayPal.
It's got 289 pages, with some of the wierdest subjects.
One of the cheapest laughs you can get and a source of possible model subjects, especially if you're a fan of Walter Christie.
Divided into different eras, it proves that there are still nutters out there - one of the post WWII designs has a tank/submarine combination!
Of interest is the patent in 1969 for a vehicle that is almost indistinguishable from the Gepard and the patent assigned to Contraves. Some of the modern stuff will seem familiar to readers, which shows that some of the stuff was well thought out.
A fascinating collection of military vehicles throughout the 20th century and well worth 3 bucks!