We stock the logic boards, drive gears, belts, and remotes that cover most chain and belt-drive openers still running in homes from the 1958-1991 build era, since that's what we're replacing most often across this service area. Battery backup units and newer safety sensor kits are common too, since a lot of these original openers predate the sensor standards that are now required. What we don't carry on the truck is every obsolete part for every discontinued model - some openers from the 1970s and early 1980s used proprietary gear sets the manufacturer stopped stocking years ago. When we hit one of those, we'll tell you straight: repair isn't realistic, and replacement is the honest answer. We'd rather say that on-site than order a part that takes three weeks and still might not fit.