The 24-3 I have is a bit of an oddity. It's not a factory custom or "one of", rather just a 6.5" that someone chopped down to 5".
Since I prefer 5" N-frames to either 6" or 6.5" I was delighted to come across this on one of the internet auctions. Got it for the starting price of $500 which was either a bargain if you like it, or a rip off if you like the 6.5". (smile)
Dave