1993, I just realized that I said "2 hrs. south of Oakland". Actually, it's about 1.5 hrs, as I'm in Salinas, CA.
And as for turning in goodies to homeowners, you'd be surprised how often they just say "keep it". Or here's what I'll do too: When I'm done, show them all the various coins, and give them to them (yup the clad and '40s/50s wheats, common mercs, etc... which we all know are scarcely worth $1 each

). Then I'll have 1 token or a single key date lincoln or merc, and say "is it alright if I keep this one, as it's a token I don't yet have in my collection". Or quite simply, if you wanted to, you could elect to just not show them certain ones you find (but that's getting a little ethical, depending on how you phrased the initial claim that "they're welcome to anything you find").
But to be honest with you, it's a blast to see the look on a homeowners face even when you part with a good coin. They will sometimes get excited and turn you on to other tips/sites, or implore you to try their neighbor's yard with an introduction, etc... The way I look at it is, even if I had to part with a goodie, it's still fun to hunt. And you can take a quick dig. pix for your boasting rights, even though you can't keep it. I have parted with a few reales, and a silver dollar. But I confess that one of the $20 gold pieces I found, I did keep my mouth shut

That one was just too hard to part with. In that particular case, I didn't plan on holding back a truth, so instead, I just waited for the farmer to ask "what'd you find". Instead, he merely says "if you guys are done, I'm gonna be locking the gate now". He never asked, so we never volunteered the info. I had to do a double-take re-think, and try to remember my exact phrasing upon getting the go ahead to hunt this little lot (where a stage stop had been). We did say "you're welcome to whatever we find". But when he didn't press on us for a show-&-tell, neither did we bother him thereafter