I just went thru this with another Hartzell acquired company. The exhaust on my IO-240 was in need of some TLC after 20 years and 1000 hrs . so based upon the recommendation of another Kitfox guy with an IO-240 who had work done in 2020 on his exhaust by Aerospace welding in Minnesota, for a very reasonable fee, I shipped mine off to them for service, noting that its now called Hartzell aerospace welding. I about croaked when I got the estimate from them on the required repairs. I ended up biting the bullet and having them do the work , but it was a tough pill to swallow. You can be certain prop prices will be higher. Bruce N199CL