Mine developed a nasty leak this year, I rebedded the frames, installed new gaskets, using silicon to fill the "track" , new o rings and the lube that comes with the rebuild kit, and they have gone back to the intermittent drip.
I'm open to any suggestion at all to stop it. It seems like the water is collecting in the catch for the dog, which would suggest it's coming in the hole the dog mounts through. The o rings are not terribly snug to the shaft, and the flanged part on the outside of the window does touch the new gasket, although it looks like there's a good seal, but apparently not. The gaskets were installed with care, and the bolts on the dogs are snug, but not too tight.
Next is to apply the water torture test and watch closely from the inside to see how its getting past the seals.
Maybe you guys are on to something though, you can't tell me the nozzle on the extruder is the same as when these gaskets were made 15 years ago.