Four times so far I've found largish amounts of money in public. First, while I was on holiday in Cornwall, I found a purse with about £30 inside a phone box. The only identification in it was a film-processing slip, so I went to the chemists that issued it, persuaded them to give me the address, went to the cottage and knocked on the door. A woman opened it, I said "Did you lose this purse?" She simply said "Oh yes", snatched it from me and slammed the door! I waited for a couple of minutes, but she didn't reopen the door.
The second time I was on holiday in Wales, found a wallet outside the Post Office. It had about a £100 quid in it, plus stuff that indicated it belonged to a pensioner, so I handed it in to the Post Office, who confirmed that they knew the owner and that he was indeed a pensioner. They promised to give him my name and address, but I never heard anything more.
The third time, I found a purse stuffed with notes in the street i9n my town. This one had the owner's identification in it, so I posted it anonymously back. And got a really nice thank-you letter back!
I had used an old padded envelope to send the purse back in, and she had discovered my address by peeling off the label that I had covered it with.
The last time, I was walking with a friend, and we noticed lots of notes blowing along the street. We collected up all that we could find - it amounted to around £70, and we split it between us.
I reckoned I had finally got my just reward for all my previous honesty!