An evening on the spanners and it's sorted.
Removed front struts (a pain to undo the top bolt) - refitted them upside down (tried to move the circip on the platform to create more height but there was no way the spring would refit so simply fitted it upsidedown as instructed.
Turning to the rear suspension I removed the struts and removed the circlip on the spring platform and moved it down to the next grove (1"). Refitted the shocks and' with the platform rings unscrewed to the max I have 1.5" between DD and chassis rail on full droop.
Lowered everything back in to the ground and hey presto I've got 80mm under the sump, 125mm under the chassis rail at the engine mount and 140mm under the chassis rail at the front of the rear
wheel arch.
Feel quite chuffed now as I've learned a bit more - but there really should be a few more clues in the Assembly Guide.
Andrew