Any of the 1980s Japanese touring frames should fit the bill. Look for Tange #2, Tange Infinity or Tange 900 tubing, all of which are relatively thick-walled and compares with the tubing used in the LHT-- well suited for touring. Plus, they made plenty of frames in that larger size back then.
Some models to look for:
Schwinn Voyageur (made in Japan)
Specialized Expedition
Bianchi San Remo (made in Japan)
Shogun 1500/2000
Lotus Odyssey
All of these bikes have stout tubing as well as touring-specific braze-ons for fenders, bottle cages, cantilever brakes, etc... These bikes were made either for 700c or 27" wheels.