Definitely a ROCKER with my beautiful Norton Dominator twin! Had a great girlfriend at the time, sittting on the pillion with her hands in my pockets to keep (them) warm
There was a finger lever on the L/H handlebar that when pulled, lifted the exhaust valve (I think) to release the huge compression on such a large cylinder. If you got it wrong and you pushed down on the kickstart as the piston came up on the compression stroke, and it fired, the kickstart litterally threw you off the bike!
I was all flick up hair black eye liner, pale lipstick and Mary Quant, so fitted neither of these images. Spent a whole month's wages on a pair of pink suede knee high boots, but I did go to the Hammersmith Palais a few times, does that count?