Eastern Marine is an odd name for Travel Trailer/Fiver Brakes but they have a lot of them and run periodic specials. You might want to get on their email list. They all that many emails to aggravate you and the trailer brake sale prices are excellent. I've used them only for Boat Trailer Brakes and other Parts. They've been excellent and the people you can call about parts actually understand parts. They've gone and looked at parts, taken measurements, etc. for me over the phone.
Oh, I'd replace the shoes (or buy new assemblies) and probably NOT use the "easy lube" system for 1. Drum Brakes that 2. Don't get submerged in water like a Boat Trailer. Or at least your TT better not get submerged like a booat trailer...