BTW, there was a tempest-in-a-teapot "issue" with the 624s. It was battled out elsewhere on the forum in 2009.
Short version, as affirmed by Roy Jinks: some were made with the cylinder long enough to accept .44 Magnum rounds. They were recalled to fit shorter cylinders. When that was done, a red-circled "C" was stamped ON THE BOX! No mark was put on the guns. Luckily I got the box and all papers with mine, and the box has the "C". Frankly, if I had purchased it new I would not have had the cylinder replaced. I load a ton of .44 Magnum cases, much of it at Cowboy velocities, and therefore much of it well within .44 Special pressures. I would have been able to use those in this gun and, "YES," they are marked. Might also add to collector value, though that has never been important to me.