If you plan to do some serious touring in this old rig have entire brake, engine cooling system and suspension components checked and repaired as needed.
Obtain proper wheels for modern radial tires and proper RV tires. Your house battery and converter charger should be tested, battery(s) replaced and modern converter charger installed. Learn about testing and servicing the 12 volt DC house battery system, most appliances and furnace need 12 volt power in addition to propane or 120volt AC power. Your fresh water pump and plumbing system may need replacement/fixes. If you have an RV generator it will come in handy at rest stops, etc. The roof AC and dash AC are also necessary. You may need new awning fabric. Check all exterior lighting. You have a new hobby.