Panaracer also makes the Col De La Vie Randonnee in 26 x 1 3/8 as well as a T-Serv in that size.
I've been riding a set of K40s on my 1956 Rudge since 2015 and they are great. It's not a daily rider, so they haven't worn through. They offer decent puncture resistance (I'm in Philly and that's a big issue in the city.)
A set of 650B wheels could always be laced up for a Raleigh pattern bike for a wide selection of tires, but considering the ubiquity of this size around the world, I don't think there is any shortage of options.