Well not conclusive right now, But after a few emails with the reseller I bought the radio off, it seems that there was a running change recently with the multi function units to coincide with these new 2.4ghz sets from Futaba.
Apparently the box of the new multi function units has some slight colour/text differences and reference to the new 2.4ghz systems whereas the older still has reference to the AM 4VWD units.
And after picking up a Leopard 2a6 last night with the reference to the AM set inside, I find it unlikely this unit is going to work with a tank either.
I have emailed Futaba Japan and am waiting for a reply.
So options for me are:
1, Replace both multi function units with newer models, replacing both AM radios with 2.4ghz Futaba sets and also with the tank (lol I doubt anyone would consider this!).
2, Buy another 4VWD set for the tank, just roll AM style, risking runaway models and party like its 1999. (Possible)
3, switch all 3 over to an aftermarket 2.4ghz set with multiple memory and receivers (like the Airtronics set a few of you guys use) and run a dual rate setup and sell off the Futaba sets. (Probable)
4, buy 3 hobbyking 4ch 2.4ghz sets (as these work) and sell the Futaba sets (probable).
Any suggestions and feedback appreciated
Regards
Neil