£20 i don't think so,
but like ttask says ,vin number and reg number would be the easiest and cheapest option.
as the impression method takes time.
you also need not remove the barrol.
have you concidered the possibility that you might have a large nose--chin..
and maybe better suited too an open face helmet that doesn't have any obstrucions such as chin and nose guards.
good luck with your choice ,, punch..
it's just that a number of mates and work collegues went for the low down ride and custom looks,
but all of the chrome turned orange over a short period,
maybe some of them neglected them ,but not all of them.yet they all turned orange.