I had to replace the propane tank on my Catalina 28 Mark II. I purchased a refurbished tank which is the same shape and dimensions as my old tank. With the new tank in place the regulator no longer fits into the recessed hole in the lid. As a result I can't close the lid when the lines are attached. It appears the the problem is that the new fittings on the tank (which were replaced as part of the refurbish) are not the same shape and size as the old ones. Any suggestions?