Before price increases I received both the life time National Senior Pass (Golden Age) , and Disabled Veteran (Golden Eagle) national passes around same time and have used them extensively at all federal public campgrounds. Also have the Oregon Disabled veterans free and 50% percent state pass plus Nevada and Texas disabled vet pass for their state parks. American Land & Leisure in California honors my 100% Disabled P&T ID (military and VA ID cards) for 50% discount camping at some state parks.
Have used all extensively and only occasional use of overcrowded private RV parks with nose to tail parking while in transit. Life is good and payback is sweet indeed.
Disabled Veteran is also a disabled Person for those who like to argue.
I use Blackstone Labs as well. The keep a record of each sample from each vehicle and the report shows all samples over time so that there are trends there to indicate what is happening in the engine. They do the same for a transmission. They also make recommendations about how long you should go between oil changes,