The header is from an F but the muffler is not. It looks like you can't get the filter off without removing the header but you can. The brake pedal pivot is positioned differently between the K and F bikes and the K bike pedal will not work without some type of modification or possibly hanging the exhaust a bit lower. Could also try an F pedal. It has been done so maybe someone with first hand info can chime in. On the middle pic the stock F muffler is hanging lower than it would on an F bike to give room to clear the passenger footpeg and give the pedal some clearance. If you are keeping the F header I think the existing solution is not that bad, just needs to be cleaned up a bit/paint, PC, or chromed. You can see how high the pedal is positioned on the K bike.
76F header
K bike with F exhaust
76F brake pedal