We have put lifts on everything, this is one that someone else built. Ours we just had on each side 1 pipe slide in another one, and cut a slot all the way up so the platform tabs would fit through. Then just hooked a electric winch under the platform somewhere, and a bearing and 2 washers for the cable corner at the top. Use a 2500 lbs winch or better the 1500 ones don’t last too light. I will take a picture of one of them when I am in that yard, what is the issue? Old age?Does it need to go flat on the ground and go up level with the top? That’s what we have built. If you need more ideas just message me , when it comes to things like this a guy just helps no questions asked.
In other words, it can only be utilized while it is turned on, whether you stand or walk up. Although I am unaware of the upkeep costs, your realtor from hinchong.com would be a fantastic resource to consult regarding value. Although I'm sure more buyers are frightened of it than you are, it may be a significant selling point for a larger population (elderly/disabled). Perhaps your area is younger and doesn't appeal to that market. I apologize for not having a response. They want to get the sale done. Not the realtor's chosen home inspector, either.
Saw one this year during a farm tour, platform flat on the ground, used a massive screw inside a slotted pipe that elevated the platform. This was on a 4WD tracked tractor, so dust and dirt probably not as bad as a combine, but he said there are not many plug up problems, and banging on the pipe usually cleans it out. When at the top, it just swings in and sits on the normal platform before the door. Didn't look big enough for a wheelchair, but not sure if I have ever seen any that are.
Friends dad was wheelchair bound, and he had a seat that he would ride up and then somehow manage to get himself inside the cab, but can't remember how he had that set up, definitely home made.