A number of years ago I saw lots of K’s on Ebay with gold pins. At the time, all K came with silver pins, or so it seemed. Also some poorly made bamboo boxes. @mulveling would know if these were genuine.
@terry9 Some (most?) of the older Koetsus really did have gold pins. My vintage Musashino Onyx has gold pins - technically I think these were produced (in part or whole, not sure) by Musashino Audio Lab for Koetsu. Today, Koetsu treats them as Koetsu all the same.
For the vintage models, there are so many variations, that beyond a smell test you really need a Koetsu historian (more than me, I top out at "enthusiast" lol) to know what you’re wading into. Hearing that old Onyx for the first time is one of my top 3 most vivid audiophile memories - it was absolutely amazing, and I have no doubt it was 100% original, but alas its stylus was worn and it was showing very poor tracking performance on inner grooves! Now I have it as a hybrid of old and new style Koetsu (modern Onyx coils, cantilever, and stylus, but kept original magnets). I can tell you the modern Koetsu guts are much more detailed & punchy sounding, and the new Platinum magnets are smoother and warmer to balance that out. Ah, but those old coils surely did have some sweet magic in them.