In the past on my old boss's "F" I have ground them with a die grinder to get the gaps between the ribs open and cleaned up, that works to get you by a couple more years.
St Johns Welding at St Johns Kansas. will rebuild them or exchange them for a rebuilt set. Get the wide space bars, (every other tooth knocked out). I got a set of these for my F2 and what a world of difference. Would never go back to standard factory bars.
I have a set of Ausherman bars in my l3 that are at least 10 years old and show no ware at all. I know they are still in buisness because a neighbor just got two sets for his M3's this spring. I would think they would have some for a K and if not could rebuild yours with no trouble. If I get time I will look up there number for you in a day or two. Good luck
I had a set of Aushermans in an old K that were in there when I bought it used. Used the combine 12 years and never did wear the bars out. However I heard that Ausherman got bought out and the new bars are junk. Therefore went to ST Johns. Take this for what it may be worth.