Wasn't me - I just participated in the discussion with my many opinions. Yes, both MacShops and Midland Reproductions are no longer viable suppliers, but the market is very slim, and eBay is almost like going to the store, except easier to shop and you do not have to stand in line at the register.
If Atlas sells the domes separately, that would be your best bet, because the Midland must be soldered and glazed. And Mac Shops extrusions are out there, but even easier is to get some K-Line extrusions and replace their dome with a good one. My K-Line compares favorably with Mac Shops, and the windows are already cut.
The Benson extrusions were Lionel, with that unrealistic lower letterboard. Otherwise, they are quite good.
This post is out of sequence - I would leave the rivets alone.
