Evinrude water control valve -obsolete part..

[aqua719]

I have to go back and double check, but it is either a 1990 or 92 Evinrude 200XP.  Noticed that the water flow was on the slow side so took it to my friends shop to service the lower end.  easy enough, with new water pump ,impeller, etc. the pressure had come up and showed a big leak in the water control valve.  researching, it seems that this part is no longer available. but I found a few links to a upgrade/conversion that eliminates the control valve.  Any one else have this issue, advice or can help would be greatly appreciated
http://forums.iboats.com/forum/engine-repair-and-maintenance/johnson-evinrude-outboards/648046-1990-johnson-v6-t-stat-conversion
http://forums.iboats.com/forum/engine-repair-and-maintenance/johnson-evinrude-outboards/463834-thermostat-bypass-valves