I had to hunt one on the net becasue the book couldnt be found in all MY clutter!

There are a few salient points to keep in mind with these agreements:
1. They are formal documents and can be scary to some. This is one reason John dislikes them, for good reason. You MUST be a good salesman to employ them successfully.
2. you must stae clearly the where, when, who, how, and why parts of the agreement.
3. In so doing, I suggest you leave out words like money, rare coins, jewelry, treasure and so on and simply say "hobby items of interest."
3. Also, I would use a second addendum which details any fee or percentage split - and leave that part out of the "search agreement" altogether, unless it was needed. In the case of a known treasure then it becomes obligatory - if you just want to poke around someones property for fun, leave it off.
4. Finally, you would be wise to stop thinking of yourself as a treasure hunter and call yourself a detectorist instead. Then you would be looking to have a "permission to detect" agreement. Much lies in the wording and perceptions of your activity.
Greed is an ugly thing - no sense stirring it up.