Aaahhh, a trip down memory lane. I don't recall the 1990 introduction of the "Legend", but I was quite familiar with the original 77b. There were still a few 77b and 94b in-use, when I started in about 1976-ish.
But even then, they were quickly being put into "dinosaur" class, by the newfangled TR discriminators, VLF all-metal, and then VLF motion disc. (aka GEB).
I will never forget, in 1980, my city tore out all their downtown sidewalks in an urban renewal project. Multiple metal detectors were down there every night scarfing up on the sidewalk demo. goodies ! I had my Garrett Groundhog. A buddy of mine had his 6000D. I recall seeing a Bounty hunter Red Baron, etc..... And then we saw a fellow with his sad-sorry 77b show up. We smuggly looked at him with disdain, as we sported our "latest greatest" discriminators. We felt pity for the poor fellow, for swinging that antique
Imagine our surprise, when he spanked everyone else 5x to 1x on old coins ! So much so, that the local paper even ran an article on his finds from the sidewalk tearout.
I was only in High school at the time, and simply couldn't understand it. I distinctly remember going to him, in the weeks that followed, asking him how he'd done it. He tried to explain that the 77b "didn't see the nails". But at the time, that made no sense to me. I mean, gee, we have discriminators that "don't see nails" either. So what kind of sense did that make ?
It wasn't till years later, that I began to understand the difference between "discriminate out" and "see through". Ie.: the "masking" concept.