Re: Custom 5 in 68 Les Paul RI Custom?
I have a couple of the chambered Classic Antique Les Pauls, and they have the Classic '57n and the Classic '57 Plus in the bridge. I really like this combo. The C57+ give a more rock tone than the C57b, with some mid-range aggresiveness--there's just more meat to the C57+. There is some attenuation of the highest frequencies, but I can still get some twang. I think the C57+'s more rounded tone makes it a great pickup to solo on.
For the wide variety of classic rock, blues, jazz and country that my band does, the BB 1 & 2 sets in my LP Historics work great. With the Mesa Boogie Mark Series amps I use, I don't need a lot of gain from the pickup. I have the C57s in the neck and bridge of another LP, and it is a very smooth sound as well; but in comparision, the BB 1 & 2s have almost a single coil clarity. While that works for me, it might not be your cup of tea.
The C57+ in the bridge mates well with the C57 in the neck, unlike the Gibson 490R/498T combo, where I want to run back to my amp and change the settings everytime I switch pickups. I think the C57+ is a very underrated pickup, and it might just be what you are looking for.
Bill