Hey Rutnbuck,
I'm new to this forum, this is actually my first post. I hope it helps you out....
A long time ago, one of my best friend's In-laws took me relic hunting. They loved to dig up old trash burial holes and out-houses. They didn't bother with metal detectors and for what you're looking for I don't think you absolutely need one either. His In-Laws used a probe. The probe was a 1/4" dia. piece of metal rod with a t-handle welded on the end. It was about 4-5 feet long with the end ground to a semi-blunt point. We would push the rod into the ground paying close attention to the resistance or force needed to push it in. If there was a place where the ground had been disturbed by man, i.e. hole dug and then reburied, the ground offered some resistance to the rod and then as the rod broke through the "crust" it suddenly got much easier, less resistance. The other thing that they paid attention to was the sound that would resinate up through the shaft. If the shaft comes in contact with a buried object it will make different sounds depending on what the object is made of. After a while of using the probes it became obvious when it contacted glass, ceramics, metal objects, etc v.s. rocks and roots. We were digging up trash holes from the turn of the century (late 1800's to early 1900's). The crust was only about 3 to 6 inches deep as I remember.
A metal detector is useful but it's not the only way to skin a cat. Especially if the cat's buried fairly deep. Food for thought!
Most important thing is to enjoy yourself and the adventure! For some of us, it's the only thing we'll ever find of value.
-RR-