Even though I’m foreign (Devonian born and bred) I do hope that I can use a sister BBC local Radio station of my very own to pass on my thanks to a mystery person who in all probability hails from Cornwall. One day last week my wife arrived home from work and noticed an envelope, hand written and addressed to her, on the front door mat. Unsure of what was inside, she opened it and read what was written on the small piece of paper tucked inside. Found on long rock beach! Her photo card driving license had somehow found its way onto the beach and had thankfully been picked up and returned by the person I would like to thank. So how did it find its way from a filing cabinet in a house in Teignbridge to a beach in deepest Cornwall? I will just say the next time her license is due to be renewed, it may be a good idea if she did it at home rather than asking me to fill the forms out on her behalf when I should be at work, and when I should be at work, I must stop having a sneaky stroll on the wonderful Long Rock Beach.
Is this a letter? All I see is a big block of text. Perhaps there should be some kind of salutation in the opening? I'd also like to see a clear opening sentence outlining why you are writing (I had to read your current opening a few times before I understood).
As for the rest of the letter, could you possibly group it into paragraphs to help with the understanding? Even a beginning, middle and punchline sort of grouping would be helpful. If you send the letter the way it is written now, I'd doubt the receiver would catch your meaning.