In the Flagstaff 8526RLWS the valves were behind a plywood panel under the sink. #1 mod was made during PDI when the Tech unscrewed the panel and threw it away. Not only did the access to the valves appear but tons of space under the sink opened up.
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW