norfdet,
Actually, last time I checked -- you can still buy a .357 Sig conversion kit from KT for your P-11 pistol for $175. It includes a complete top end (slide, barrel, springs, and guide rod).
Simply slide off your 9mm top end and slide on your .357 Sig top end.
You are correct, the P-40 was discontinued -- and the .40 S&W conversion kits have been sold out for some time now. However, parts are still available at the factory. You should be able to by a replacement .40S&W barrel if you need it...just not able to buy a new P-40 or .40 conversion kit. Once the stock of .357 Sig conversion kits are sold out (if they aren't already) I suspect they will not be replenished.
I know that the .357 Sig barrels have been available for $110 too.
So, it might still be possible for you to buy the .357 Sig conversion, order a replacement .40 S&W barrel...and have a three caliber combo for your P-11 like some of us other KTRangers.... :twisted: