Pierre-yves point was that even though the original kits have long gone, that's no justifiable reason to take a copy of anybodies work. There are other angles to this of course. For argument sake, lets use Slot Classic as an example. The Jaguar Mk2 that was recently announced was sold out very quickly. My guess is that ninety nine percent of those won't even see a slot car circuit, and just become shelf queens. At knocking on for three hundred quid each, I can understand why. So when someone copies it and offers a kit at a very reasonable price, then the option of a usable slot car becomes more realistic. A kit that costs in the region of £30 will of course attract people who wish to race them. Personally, if an original is sold out and copies do appear, I can't see it doing anything than increasing the value of the original. However, I do see Pierre-yves point, that it is still theft however you wish to wrap it up.
I have heard of a retail outlet in the US that buys up as many of these original kits as they can, not just PSK but pretty much every brand and waits for the value to rise. Now then, what's right and what's wrong? I think it's a problem that really has no solution.