Got the seat unit sorted - made a base with some alloy plate then stuck it together with a few 6mm bolts & some P38.
Made a real SIMPLE, LIGHT & EASY method of removing it..... I used a bucket handle

as the wire is some sort of spring steel, and it passes thru' the seat-base alloy into some lugs on the seat rail.... and is a "spring-fit" !!!! The nose has a tang that fits under the frame, beneath the tank.
The wire is then clipped onto the seat nuts ......
Next was the front muddy. It arrived today so I spent lunchtime (an extra long one) trimming it up and fitting it.....
Looking good now - ready to pack for painting .... but I'm still undecided what colours......
The combo for TANK - SEAT - MUDDY will probably be BLACK & GREEN... but just not sure what to paint in what colour

And on the 7th day... Zeds were created!