Dan,
I do have some infomration on the load leveling system that I got from a Chilton's manual (it shows a pictorial assembly diagram of the entire air reservior tank). I also have a dcoument that explains how the entire system fuctions.
As for the air filter, I have a NOS filter in the bag similar to the one that you posted the pictures of. If you want, one of the times when I go to Quincy to see my Mom, I can meet with you to show you the filter. As for the documents, I can scan them in and e-mail them to you if you want.
If you have additonal documentation on the syem, I would like to add more to my information collection. Take care.
Jim