There's a forum that is specific to vintage detectors. Sometimes on that forum (if you read back through archives of posts), some guys will relate about coin-hunting in the 1960s, for instance. Here's the link to that forum (hope it's ok to put it here):
Vintage Metal Detector Forum
But as virgin as things were, you have to remember that the detectors were very crude, lacked depth, had no disc. (except some early TRs which inherently went silent on small iron), etc.... So unless someone back then was very wise to being the first one under a ferris wheel, or at the base of a concession stand on the beach, etc.... it wasn't as "easy going" as you might imagine. I knew some guys who were the first in my town to get detectors. That would have been in the mid 1960s. And yes, back then all the coins were silver (maybe just the very begginings of clad anyhow), and yes, tabs weren't in widespread use till the mid '60s and later I think. But surprisingly, they might finish a hunt at a school yard, etc... with only 5 or 6 silver coins, the obligatory wheaties, etc.... They were bedevilled with foil, was their nemesis, and no way to disc. it out.
If you fast forward to the mid 1970s, when disc. machines first started making the rounds, there was actually a lot, if not more, silver being found then. And there was another mini "rush" in some circles and some areas, when the first motion discriminators hit the market in the late '70s (6000d, red baron, etc...), simply because they offered more depth, and disc., all at the same time.
Another example: There was a particular fellow who by all accounts, was the very first to be working a particular ghost town in Utah. It was about 1967 or so, and he had a machine that could get coin sized objects to perhaps 2" deep. But since he was the first one to hit the place, targets abounded! A good hard day's hunt would yield 2 or 3 coins or a token or whatever, amidst the myriad of targets he had to dig. 5 yrs. later, machines like the 77b, etc... came out, which had more depth, smoother, and able to knock out iron. This brought that same town "alive again" for him, and his target counts went up. But after awhile, he struggled to get "2 or 3 coins" again for a hard-day's work. The fast forward through other evolutions, and each time a new machine/type would come out (VLF, VLF disc, 2-filter disc, etc...) each time he'd find targets that the previous generations missed. But oddly, through all those times, the "standard" of a "good day", was still the same as back when he'd started: "2 or 3 coins".
Thus with a few exceptions of guys who stumbled onto something very very thick, the reality is, detecting was hard, even back then. I started in 1976 or so, with a 66TR, and back then, we considered a 3 silver hunt at a school yard to be respectable. Fast forward to today, and .... even though I've got 3x the depth, and all sorts of bells and whistles, it continues to be about the same, on hour-per-hour results: a 3 silver hunt at a park or school yard is still about the same.
