O.K. We could add 'Official Contractor' to the bottom. We can be ambiguous in our response from S....i or Y....a breakdowns when they ask dumb questions like, 'Are you official?' or 'Are you authorised?'
Jeremy Clarkson type replies. Works for him and he's rich and doesn't have to earn a living, so it must work.
If they don't like it we can point out they should have bought an ST. By the way, they'd better hurry up 'coz they're not making anymore so they'll miss out and be sad forever.
Or something.