Many thanks to all for your willingness and efforts to help me to Identify the tank.
It does has similar features Michael.
This tank has a very wide backbone tunnel. Haven't measured its volume, but it would not be a lot.
Wide backbone tunnel would almost suggest a cantilever Yamaha Mick.
Those ribs that you and Geoff are thinking of may have been CZ roadies - pretty sure they had them.
Nice score on the tank anyway,
Pete.
Makes a lot of sense Pete.
Ola Martin, I really like this tank and I was and still am pretty excited about it.
But since it is a key missing component for you, I am thinking about it. If it goes anywhere, it will be to you. I need to think on it first though.
The reason I was wanting identification, was so I could set up searches for more of them
Probably not likely now though.
Thank you everyone, Mick.