[hharney]

Ed / Mark

The D model tanks do not have the large interconnect between the mid-main and the inboard aux. The D model has the older style main tank and independent auxiliary tanks. The G model like yours has all tanks interconnected and the D is separate mains and aux's. The D model also has a service port.

The G model is the blue figure attached and the D model is the white figure attached. That should explain the difference. Not sure I understand why the fitting cannot be repaired. I have had to repair a fitting like that on my main tank (inboard, mid) and it was welded with no issues. Sorry to hear the problems.