Grumman Fire Trucks are indeed only Grumman. Existed 1976-1992 (founded after buying Howe Fire Apparatus Company by Grumman). Names of their models - Minicat, Attackcat, Wildcat, Firecat, Aerialcat and Panther:

http://www.bensware.com/firetrucks/spotting/index.htm
http://www.powells.com/biblio?isbn=9781583881651

And second question - maybe worth remove Grumman and KhPZ from shorter vehicle list on the main site and put instead them some other makes, more deserves?