The general consensus is no,although from time-to-time someone will come up with a pair that appear to be. Who can say with absolute certainty that none were ever produced?
f.t.
And in a recent posting, there was a claim made that N-frame Coke stocks were sometimes converted to fit a K-frame, and I suppose that is possible. But the "conventional" wisdom is that there were never factory-made Cokes to fit K-frames.
I saw that ad, too. My guess is he is just throwing out words he really doesn't understand kinda like the guy who was trying to sell a "vernier dial caliper".
I've noticed the larger checkered area on some of the non-relieved K-frame targets and I have a set myself just like this that even have a coke profile to them. The consensus I've read over the years is that while they share some similarities to actual cokes they were never catalogued or marketed as such and are thus just plain diamond targets. I personally really like them and would pay a premium over standard k frame targets.