I may have been thinking of this thread perhaps ?
http://www.mapleleafup.net/forums/showthread.php?t=8997 however I thought I'd seen a written reference somewhere I'll keep looking.
At this stage (something like 20 years ago) I can't remember if the remains of the one I found had 60cwt axles however it was definitely a 12 cab on a 15cwt wheel base with the remains of a GS body it certainly didn't appear like a reworked GT.
Pete