Marconi, Now I have to agree with you because these numbers just don't add up. Good eye to pick up on that. I strongly suspect there is some mistake in these specs because these two antennas cannot have such different lengths and wind loading. I can understand a weight difference but the wind loading is a function of surface area. I'm thinking nearly half of the MR elements would need to be made of wire before the wind load could drop almost in half too.
One other thing I wanted to point out is that many of the antennas Tom at Maco designed have unusually long reflector elements at 222 inches or 18.5 feet. The reflectors are noticeably longer than the original Wilson designs at 216 inches. At first I was sure I'd be able to extract more performance adjusting the reflector length shorter.
After two days with the field strength receiver and attenuators, I'm convinced Tom did a great job! Nothing I could do with the reflector element length could improve forward gain. It would appear he has already put the effort into getting this perfect.
