newyopper,
If you were proactive and wanted to advertise for business, this format may interest you:
Dear (Property Owner's Name),
I would like to introduce myself. My name is (Name) and I have lived in (Your Town) for (Number of Years). I am (Age) years old, (married/single) with (number of children). Normally, I would prefer to meet you in person, but I feel that a letter beforehand is a better approach than just knocking on your door at an inconvenient time and invading your privacy.
I have been engaged in the hobby of metal detecting for (Number of Years) years and find it a healthful, enjoyable pastime that allows me to meet many interesting people. The thrill of finding old coins, buttons, etc. is very rewarding to me.
Recently, I have researched information that your property and the area surrounding it goes back many years. I would like to obtain permission for myself to detect on your property.
I want you to understand that I always respect the property that I search and leave it in the same condition that I found it. Normally the targets are no deeper than 4 or 5 inches and I retrieve them such that the ground appears not to be disturbed. In addition, I would like to offer my services to you.
Perhaps you or someone you know has lost a valuable ring, a cache or a farm tool. I would be willing to assist just for the thrill of the search. I have enclosed a self addressed stamped envelope for your convenience and would be happy to meet with you if further discussion is required.
Thank you for your time and consideration.
Sincerely,
(Your Name)
(Telephone Number)
Don........