http://www.localhistory.scit.wlv.ac.uk/Museum/Transport/Motorcycles/Shacklock.htm
Halfords cheap 8mm low pressure LPG gas hose from the camping department makes great fuel line.
And Maplins do a really good brake light switch for £2:
http://www.maplin.co.uk/low-cost-standard-microswitches-6453 
