I am intending to take to Kempton on Saturday the CB500/4 engine that came with the job lot of Honda bits. It is very scruffy, dirty and seized. Photos give a good guide. Number starts CB500E201****
I would think it's worth £200, I 'may' be able to deliver locally, West side of London, Surrey/Hants/Berks border.
I will also have some carbs, mudguards, rear chain guards and a couple of pairs of shocks with me, plus some boxes that will need rummaging through.
Cheers, Tony.