[mickmate]

Look for the narrower arms and axles previously listed. The centre section is the key as longer arms and axles can be shortened by someone with the equipment. Look for a centre section with two tags under the bolts for the back cover. One will read BPL (British Power Lock) the other will be the ratio either directly or as a fraction. 3.54 is the desirable original ratio. If you find two let me know, the scammers round here want $600 for a pumpkin only. Need more info, ask here. Good hunting.
Cheers Nick