Late 90s, it would have been. I used them on a CTC ride to Calne when the ride leader took one of those Sustrans abominations that started as tarmac, turned into gravel and, shortly after that, actual sand. Not the ideal tyres for it.
A lot of us back in the day ran gravel, dirt, and sand on thin tires like those, I did with 19's, not idea, not very fast either, but we did, through that experience I gained a lot of knowledge handling a bike on rough terrain, I have no problem riding gravel roads out in the country these days on my bike that has 25c tires while others stay away from those roads with the same size tires I have, no they won't ride those roads without a gravel, hybrid, or a MTB.
A weird story but true but weird. Back in the early 80's I was on a road bike with 19c tubs going down a mountain grade pretty fast, at the end of the road it came to a T with a stop sign on all sides, I was going pretty fast, slowed down just enough to make the turn while blowing the sign. A cop was parked off to the side on my right of the T and I was turning left, next think I know he's behind me tapping his siren and telling me to stop, I was up along a guard rail and didn't want to stop there due to it being on a curve and it was a narrow mountain road, so while I was looking for a spot to stop I noticed a trail about a foot wide going up into the forest and up a mountain, not real steep but going up nonetheless. So, realizing that my financial freedom was at hand I went up that trail while he was screaming at me on the PA to stop and come back now. A few of the areas were pretty rough and steep and had to dismount and carry the bike some of the way, but I got to the end of the trail that went about a mile, and ends up on another mountain road, so I took that road in the opposite direction of course. That cop had no clue where that path ended up and I doubt he walked it! I was in college at the time and the last thing I needed was to spend money on a ticket, I was really glad that path was there, though I had no clue where it went or what sort of trouble I could run into and not be able to get myself or the bike out of there, but it looked like people had hiked it so I wasn't overly concerned. The other weird thing about that story is that I always carried 2 spare tubulars with me because they got flats pretty easily, I didn't get one flat on that trail!