Thanks - not much to look at atm, but they'll be butterfly pretty shortly.
Ive been speaking to a couple of friend laminate/design engineers recently and have come to the decision to make the 2 tanks into one that'll utilise the under seat storage space. Mounting will require removing the top subframe mounts and pivoting it down to slip the tank unit into place - custom under seat/rear taillight set up required. As my main design requirement was max capacity (= range) this will give me approx 6 lt of extra capacity without any drawbacks. There will still be under seat storage, but not as much - and abs is out. As it will be one unit it'll only need one filler (rhs which is higher when on the sidestand) and one petcock/dry break/fuel tap. All told it'll hold approx 22lt if my mathing is goodest???
Once Ive got it fitted and trialled It'll be moulded and possibly offered to the greater good if there is enough interest. If its a dog then I'll go back to the original 2 tank idea - but I cant see that happening any time soon. (unless someone has mucho $$$$$)