Late note: (May 25th) If any builder is having trouble locating a source for the 1" diameter 316 stainless steel ball, I found an ebay store ToolSupply . The ball bearing ships anywhere by mail and is actually a couple of dollars cheaper than McMaster-Carr who declined to process my order.
It weighs about 3 lbs and I am very happy how it turned out.
Now to get it coated and perhaps build a main hull to mount it on.
Other recent news: my 26" Northstar 600 is now listed for sale. Here is the link.