As I'm a stingy git, paying the British Embassy UKP15 to photocopy my
passport and sign a form letter seems too much, what with all the
additional hassle of getting to the consulate.

However, I understand that you can get any professional of any
nationality to do the deed, but unfortunately I don't know the wording
required. I plan to ask my dentist, so if anyone is familiar with the
required wording, could they tell me please.

TIA, and I promise to send a GIF of a pint of beer for any help.

Ken