If you're thinking of getting a crank driven water pump, this guy has a few available:
http://www.ebay.com/itm/Johnson-F6B-...-/122298287187
I noticed the flange on my pump was cracked, due to an improper installation, so checked ebay and found the above. He's asking $100obo, but he accepted my offer of $80. I probably could have got it for even less, but I'm more than happy with $80. My other option was a new one at about three times that.
I just received it yesterday and I took the impeller out to check the condition. Except for a very minor bit of corrosion inside the housing, it's like new. A light scuff with sandpaper and it cleaned right up.