I think many of us have been there with you, some with a homeowner hawking over our shoulder, or thinking that everything you find is theirs unless they don't want it.
I've hunted hundreds of private yards over the years knocking on the door cold turkey, and try to make sure that they are aware that I plan to keep everything I find,
unless we make other arrangements, like returning family jewerly or the like.
It gets a little tricky when you hunt the yard of a friend or family member like you did. I found an alternative a number of years ago that worked. A close friend and the president of our detecting club lived in an old house in an old town. I had recently bought a new detector and while I was visiting, we excitedly got the detector out and went over the front yard to see what could be found. Bingo, up comes a VG Walking Liberty Half.
Who would have thought? He had hunted his yard a number of times with a Tesoro Inca and more recently his new (at the time) White's 5900 and had found plenty of good stuff. Somehow this big beautiful silver coin was missed.
What to do? Walkers don't come along every day and I felt plenty guilty of turning up one in his yard. So, I went to a good friend who happens to own a coin store and bought a duplicate, same year and mint mark. Same condition as best could be matched. One Walker for him, One for me.
I think I have the store bought one for my collection, but I'm not sure as I remember back on it. I could just a well have given him the store bought one to have.
Back in the early 90's, I was hunting an old ghost town with a friend on memorial weekend. One of the local clubs had a big outing there each year. We would typically hunt with detectors as well as do some sifting. The ghost town was known to have given up quite a few gold coins over the years lost during town fires and floods. As luck would have it, my friend and I were sifting around the base of a building and SHAZAM
, out comes a beautiful 1881-S $10 gold piece in XF cond.
We did the gold dance and everybody camping out came over and celebrated. It was great. What to do with the coin? Well, we had agreed to share what we found so I devised a resolution.
This time, I went to the coin store and had my friend appraise the coin and tell me what he would sell the coin for if it was in his shop. He gave me a price. My friend typically sells all of his valuable tokens and coins and keeps the interesting stuff for his kids in a coin collection for each. He was interested in the $$. So I gave him 1/2 the retail value of the coin and put the coin in my collection for a number of years. It was a little expensive, but hey, it was a gold coin. How many of those turn up on a regular basis? Too, he is a best friend and I did not want any feelings of resentment over how much I gave him for his half, so I gave him 1/2 of the retail price.
So there are alternatives from walking away from something you would really like to have in your collection. I'd say go find yourself a Large Cent of the same year and put it in your collection. Being that you knew him, you could have offered him a deal that you keep the original and buy him a stand in piece to look at, but it is a little late for that now.
As for what he did to the coin, I've never liked taking the toning off of copper coins or brass tokens by soaking them in an Apple Cider Vinegar / salt solution. (It forms a mild acid). You can fix it to some extent by placing the coin in a very small bottle that has a lid, lighting a match, placing the match in the bottle and covering with the lid. This contains the smoke inside the bottle. You will notice that doing this a few times while flipping the coin over between treatments will darken the coin or brass token giving it a 'false' toning that makes it much more appealing to the eye.
Back to the Large Cent trouble. Most of the time, private property owners are concerned about something valuable being found by us and they loose out completly. When I am arranging a hunt with a property owner, if who keeps what comes up and it is a sticking point and I still want to hunt the property, I typically offer them them half the value of anything worth over a certain value like $100 or if a cache is found or something along those line. l offer to have my friend that owns the coin store be the 'mediator' for it and divide up whatever needs to be divided.
Most of all, you want to be fair and honest and not have regrets that you had to sneak away with something tucked inside your shoe. If it is clear ahead of time then you can walk away not worrying about it.
I don't always show everything I find to a house owner. Before I leave, I do thank them for allowning me to hunt and may show some of the odds and ends that I've found and may leave a little momento like a wheat penny or something. I am genuinely grateful they let me have a look around, why not show it? There have been a number of occasions, while saying thank you, an opportunity has presented itself to hunt a neighbors or relatives yards. I've gained their trust by being fair and open and they feel good about passing me along.
Anyway, hope this helps.
Best of luck out there.
Rich (Utah)