We have returned as Airstream owners after a 25 year absence, and I'm just getting to know our newly pruchased 20' 1965
Globetrotter Twin. My understanding from the previous owners is that it has a combined grey/blackwater tank of approximately 10 gallons and a fresh water tank of around 30 gallons.
Questions: (1) Do those capacities sound about right?, (2) Is there a relatively inexpensive way to increase the grey/black water capacity?, (3) Any advice on installing a tank monitor system, like the SeeLevel? Thanks in advance for any help you can give me.