I've got 3 different ones. They are castings. An original Rigby, a Rod England, and a Pete Allen. The last one is a 1 incher. The others are 1-1/8".
I'll try to get you some pics when I have time.
As an aside, Pecatonica should carry the 1" ones in stock. However, you have to use the L&R bar lock and drip bar with that set-up.