A LHB is different in construction when compared to a Cheyenne. The Cheyenne consists of 4 huge leather panels that all more or less cover the full length of the jacket. The cutter will have to find at least 4 full skins that are large enough (and display a good thickness throughout their full length) to be made into one of the "Big 3s".
Sizes larger than 38/40 are impossible. And today Aero refuses to make a Cheyenne in goat.
I don't know about a LHB. If you can live with smaller panels it should be possible as it features the false belt on the back which makes dividing the panels easier. A standard 50s or 30s HB shouldn't be a problem as long as you don't need a 44 or 46.
http://i211.photobucket.com/albums/bb50/lscott0001/goatskin2.jpg
http://i211.photobucket.com/albums/bb50/lscott0001/goatskinhalfbelt-1.jpg
Here's the pics of the LHB in russet goat