Thanks for the picture and for everyone with their input.
EDIT:
I've just been down to check the tank again. Yes the rear mounting hole is round and the front elongated with both taps facing slightly backwards.
Thanks to the forum I've managed to work out which two wheels belong to the A7 rather than the plungers. The none splined side isn't as wide and the pressed on cover isn't as big as far as I can tell.
Plus while hunting for the wheels I found another large box with A7 parts in it, 2 more cylinder head (one has had all the fins cut off it but the other is stock) 6 pistons, a couple of rocker box sets, some footrests a few idler wheel and some cam shafts. There are 4 sets of cam but looks like only one set is worth anything. That might well come in handy if the set in the motor are less than perfect.
It looks like at some stage the bike/engine has been raced as all the rocker have been polished and the idler wheel drilled, I guess its been run on dope or something for the cylinder heads lack of fin. There are also some rather high compression looking pistons in there that show rather large signs of abuse!
I'd like to restore the bike to standard but the pistons I have have a rather large crown on them compared to the flat toped ones shown in the manual. Are these likely to be Star Twin pistons? Best I take some more pictures I guess.