I am pretty sure my built-in oxygen valve/regulator assembly needs to be overhauled. For those who have had theirs serviced, my question is who did the overhaul, about how much does it cost, and about how long did it take? This is in my 1997 Encore. Since I bought it last may it has leaked oxygen out. Sometimes stopping at 700 psi, sometimes lower. I did a test where I plugged a tube into the low pressure port and put the other end in a water bottle. Even with the valve lever fully off a co