This site will answer your questions.
http://www.keystonerv.com/previous-y...tana&year=2004 The fresh water includes water heater and water lines. My spects say 60 gal fresh water but the tank is stamped 45 gal. then add the 12 gal water heater and I do not know where the other 3 gallons are except the lines. Also the 76 gal gray is actually 2- 38 gallon tanks 1 for the shower and the other is for the galley.