Hi there, I've got a couple of Stihl Stihl HL-KM 135 adjustable hedge trimmers that aren't functional right now. The problem with both units is that the angle gear on the side of the attachment wasn't lubed often enough and the angle gears that allow it to pivot are worn to the point where they won't drive the cutters anymore. So, is it cost-prohibitive to replace these gears or is there a supplier, online that sells them? I've got them apart in the shop and just hate to scrap them! Thanks for the time. I look forward to your replies.