I recently discovered 4 high-pressure LP leaks between the vapor valve and the regulator on our Alegro Bus. Pipe dope had dried...not a good thing! On our previous motorhome there was a low pressure LP gauge located behind the refrigerator (outside access) and mounted in-line with the gas line. It had a rotating bezel with a red needle that could be set to match the gauge needle. It was great for leakdown testing of the LP system. (Turn off all LP appliances, set the red needle, turn off the main valve at the tank and check for a drop in pressure...the red needle made it easy at it did not move). This was great! Always there, always ready if a leak was suspected or just for preventitive maintenance. Here's my problem, I have been unable to find one of these gauges. About 10 years ago I seen one at a RV parts store for $6. I would appreciate any help in locating one of these guages, or info on alternative gauges that would be appropriate. Thanks!