I just replaced the seal on my 950SM tonight. I did the oil and filter when I was in there. It has a little over 21K miles.
My symptom was coolant loss from the overflow tank. My oil filter was wavy when I pulled it. There was no milky residue inside the engine when I pulled the inner clutch cover, but there was a little between the two bearing on the pump seal shaft. The pump shaft was worn and the snap ring behind the seal was bent.
I bought the kit from KTM Twins and their kit includes the new style seal, made of Teflon.