Update: It's gonna cost me!
Had some minor issues with cable routing (chain was rubbing against adjustment barrel) and sixth gear slipping. Re-routed the cable and dialed in the adjustment and now the Twenty rides quietly and shifts smoothly. I took it out for 15 miles today and decided I wanted dual purpose pedals; platform on one side and spd clip on the other. I'm amazed how solid the bike feels and I was more confident on it than other vintage Raleighs I've owned (Sports and Sprite). So add pedals to the list of future upgrades.