Although that is correct, I've never seen a cast iron top on a known perfectly original common 850. The only ones that I know for sure that used the cast iron top was the twins. But then again that only means I've not seen everything..lol. Tom.
A friend found one last year at Dixie in with some other parts. Miles has had a few. I also saw a single 850 at Hershey last year with the cast iron top.
It's a long story but at least one cast iron top originally came from a bulk house in eastern North Carolina, went to Indiana then to Florida then to Dixie then to Miles then to Long Island New York....oh heck it's been around....lol
This is the first pump I got after running a free ad in a small paper back around 1989, Its 100% original, chain driven pump mechanism still works. Cast iron top, roller nozzle was on it, the old man called me a week later and said I forgot the sightglass on the wood pile, bonus find, with original tag to complete the pump.
Very cool, thanks for sharing Rick. I'm guessing since it's a chain drive then maybe the cast iron tops were only on the very early ones. No matter what the cast iron top is rare.