Gas Line Won't Hold Pressure, But Can't Find Gas Pipe

[seminole plumbing]

Ive had the gauge itself leak out the back, where 2 screws are present. When we ever soap test to look for a small leak, we completely cover the entire test block and gauge with soap. Also you had mentioned soaping the "joints" numerous times. Soap the entire fitting. As perfect as manufactures are, i have personally seen pin hole leaks in black iron fittings themselves. Makes the job oh so much fun.