Yeah, I'd keep the 60's Ludwigs if I were you. The CMs weren't terrible by any stretch but sitting next to my Prolite kit probably didn't help in forming my opinion of them. They were clearly a rung down from those. The CMs just seemed kind of one dimensional to me.I have to ask because I always took the CMs as a modern drum build/sound. Even DCP videos will say CMs have "that Ludwig Sound" but they are also selling it . I guess you can trace back ~76' when they started with non-reinforcement shells but that shell formula was different....really the CM shell formula didn't start until 2001 so but maybe it's a solid lineage, IDK. I think they are fine sounding drums but this seems marketing which seems to work well....the "Keystone" name was a terrible name (sounds like a speech address) and think why they didn't sell well and change to "Classic Oak" which was smart, people like "classic" and "Ludwig" together I think.
I'm was actually considering selling my 60s Ludwigs, but I'm on the fence now though....
I actually had 10/13/16 on my Horizons, it's a really nice interval and complimented the N&C build very well...some say it takes getting used to but I found the tuning to be very easy. The walnuts would probably be my first pick if I were to get N&C again, would love to hear them in person someday.
RE: 10-13-16 tom intervals. I vacillated between getting a 12 or 10. I'd just had the 12-13-16 with the Classic Maples and it was meh. I'd had the 10-13-16 once before on a Sonor Delite kit and it was pretty cool sounding so I decided to go that way with N&C Walnuts. Plus, Walnut doesn't have the same articulation, or clarity, as maple so I thought the 10 would provide a more defined step in the tonal range. The bad news is N&C quoted me 16-20 weeks for the 10". They said they're slammed right now. Ugh. I'll be 4 pc'ing it (3 pc + snare) until then. They do sound killer though! I'm currently using a 14x6 Summit Curly Maple solid shell snare with them. It has unlimited crack, tone and articulation. Beautiful drum.