Just to let you know I recently saw two GPA's in Mildura in the Riverland of Victoria.. Australia..
Both were in pretty poor nick but the guy who took me to see them had owned one of them for many years using it every day around his fruit Block..
I toyed with making an offer on them but I have too many projects now.. Both the guys who owned them called them "Amfib's" as if it was local slang for them..
Next time I'm close I will take some pics and post them..