Yeah I thought guns that looked like were only for viewing purposes only? I have seen some of the guns that are cut away like you described for sale on gunsamerica, and they specified in the add that it wasn't made to be fired...
there was a guy on gunbroker, who posted up some stuff regarding clear grips for a 1911, he claimed they were professional reproductions, made from plexiglass. I am not sure if he still has them up for sale, but they were priced at around 50 dollars per set.