my personal favorites are the ones on that bike in your picture though uno, they're the real classic Funk! When I had mine resprayed I tried to get some made like that, as you can imagine the results were not the best....
Can't think where else to look for the serial number though, headtube (its big enough to get a phone directories worth of numbers on!
Can't think where else to look for the serial number though, headtube (its big enough to get a phone directories worth of numbers on!