I brought a Stihl MS391 for $5 yesterday at a garage sale with SN 177445814. Can anyone confirm that it is actually a MS 391. Says MS391 on pull start cover, but is is fitted with a genuine Stihl MS362 exhaust muffler. Very strange indeed. Original owner has pulled all the labels off so I only have the serial number on the case to go on. Other than some tree sap stain on the front, it runs perfectly and an absolute bargain for $5.