Ha - my second bike (bought after the theft of my Dawes Kickback) was a fat-tubed Claude Butler. Loved that bike... and it's still in the shed.
Over the years that old CB wore XT thumbies & rear mech (+ green jockey wheels), USE seatpost + bars, triple-butted Project 2s followed by some random Rock Shox, Merlin-built Mavic 117s on XT hubs (with snow-flake front spokes + green nipples), an I-Beam stem, Impact h/set, DX levers wt XT V-brakes... and lots of the Umma Gumma & Porcs tyres I've seen on here.
Wasn't aware of the retro-bike phenomenon until recently, but tempted to drag the beast out of the shed and use some of those old bits...
If only I'd had a Claude Butler like this one, I'd still be using it!