Monarch was the company selling the cure for this problem. Went out of business a while back, and Hart aviation buy their Line. I understand that Hart is selling the umbrella caps for Cessan 177 and 180/182 but have not started selling the moat caps yet, if at all. The way the 175 worked, was the cover plate around the filler nect was taken off, a new flange epoxed on, never cover plate and new tank cap, all PMA'd. I wish I would have bought the set when it was availabe, as I recall it was just under $ 200.00 for the Cessna 175, now it is too late. So hoping that Hart will start selling this item again. I check the for sell adds occasionally trolling for some one that might be trying to unload the C 175 kit, but no luck so far.
Tim