Hi Ron, as ever, thanks for your input and useful information.
So I'm looking for two pre-war toolboxes with central thumbscrew. I should be used to nothing ever being straightforward by now....
At least I appear to have a genuine, but later, lower toolbox. No sign of the integral mounting brackets for the upper toolbox on its mounts though.
Best have a look see if our Indian friends list the earlier box, unless someone knows where...
Rupert.