Still sounds like a work for someone.
It reminds me a little of a situation about 10 years ago where an 85 year old neighbour of a friend had shed full of disorganised (mostly) rusty old tools, many shelves of rusty fasteners in glass jars and cans, a stash of timber, and a few home made rusty machines. The elderly chap lived alone and was so frail and ill he was about to be moved into care and wanted to know what his stuff was worth. Like the chap in the OP he was hoping to sell everything as a job lot. In addition he was hoping the buyer would clean the shed out and take away the rubbish of which there were a couple of trailer loads.
Even though there may have been a few interesting pieces in his stash I indicate that "as is" nothing was worth much, but if some of he tools were cleaned up and presented in a half reasonable manner they might be worth a few $. There was no way this chap was on his own able, or at this stage even interested, in sorting out or cleaning up tools. He suggested he could do something if he had some help but I could see that this would mean at most him sitting and giving directions. For someone with a spare week up their sleeve it might have been in interesting exercise but I politely declined to help. I've been caught out before doing these sorts of a, "oh while you are at it can you clean it up" jobs before. I did offer to take photos of his machines and place an ad on GT but when I explained that I would be putting his phone number in the add and that it would be up to him to show the prospective buyers and arrive at a price for the machines he was clearly not expecting to so this. Perhaps he expected every time an enquiry came up I would drive half way across the city and negotiate the deals. In some ways I didn't blame him for not wanting to do it himself, who knows what sort of person might show up. I did feel sorry for him .
Another similar case came through a concierge service who were helping an elderly couple clean up and move out of the family home into care. The wife thought the hubby had a gold mine worth of stuff in the shed and asked the concierge service to find a valuer for the speciality tools in the shed and I ended up being asked if I could do it, for a small fee!
I said I would take a look as it was very close to my place. It turned out to be a 3 x 4 m garden shed with no machines, just a battered old bench, a few rusty hand tools, some wood, lots of rusty paint tins, and lots of junk. The old bloke was in the shed in a wheel chair working at the bench. The wife (who was much more able then he was) introduced me in a highly condescending manner, as the ". . . the valuer from the concierge service, he's come to tell us what your stuff is worth and help sort it out!" The old bloke who had suffered a stroke and could not speak very well was clearly annoyed and embarrassed as he knew what he had was basically junk and why had his wife even bothered. I was also deeply embarrassed but had a short and difficult conversation with the old bloke about his condition and quick look around and then left. From my car on the verge I called the concierge service and said that the stuff had no significant value and perhaps a garage sale might raise a few bob if the stuff was organised but I would not be able to do that and there would be no fee.