I don't know that I've ever had a vehicle that wasn't made anymore AND had the potential for hard to find parts. That white valve is a roll over valve for the expansion tank. The place I get my parts from in California still has these but not the seals. Since I had to replace both valves, I had to get the seals off the old ones and onto the new ones and then get them into the tanks. The first one went in beautifully. I put a bit of RTV around it for good measure. This one...not so much. The seal was trashed. I started by using a little less than a tube of RTV. That got messy. Then I went shopping. I found grommets for valve covers that are used to hold little filters/breathers. The inner diameter fit the valve pretty darn close but there was a little play between the seal and the tank. I met an old timer at the store and started talking to him. I usually don't enjoy talking to people all that much until I get to know them. For some reason...I like speaking with my elders. Anyway he was telling me about this stuff he sealed a gas tank with once and, low and behold, I found it a few aisles over. So I laid a pretty big bead of it on and I'm gonna let it sit over night and set up really well before I throw it back in the wheel well and attach a vent hose to the valve.
This sides all done.