The Purosil silicone elbow hose from the thermostat above the water pump is leaking a bit, so I thought I'd replace it. The original part number, 90-225-M2, is clearly stamped on the side of the elbow, so I thought it would be easy to find a replacement. Not so. I have found that the current number is 90-225-MK, but so one seems to be able to cross to it. I've been to...