Or could it be from one of those Big Red Quads that pop up in Europe every once in a while. Check it out.
http://cgi.ebay.com/ws/eBayISAPI.dll...522910053&rd=1
The guy has it listed as a TRX 300 tank, and I can't quite tell if it would fit onto a Big Red 3 wheeler or not. Another thing that catches my eye is at the bottom of the page, there are a few questions from possible bidders. The one reads, "Hi, nice tank you got there. Do you have any other parts for the Honda Bigred 3 wheeler? thanks." The seller's reply is, "Yes what is it you are looking for, and I can find out and give you a price."
So can we infer that this tank is indeed for a 3-wheeled Big Red even though he has it listed as a TRX 300??? And we know it's from '88 or after based on those decals. How interesting.......