Beammeupscottie, perhaps I'm being a bit paranoid, but if you put your phone number in your purse, and it is found by a 'shady character' , they could phone, and if the phone is not answered, call round and relieve you of some of your possessions.
But as to you wanting to show your gratitude, just go with your instinct.
Estranged Son and Future Granddaughter
To think that London, or anywhere else for that matter, does not belong to any one demographic