I'd try to find who does estate sales and auctions in your area, and look at their listings. Auction houses will often have a "past auctions" listed on their website, complete with auction listings and sold prices. See who typically handles auctions with tools, etc, and give them a call.
It takes a bit to weed through the people offering "estate sale" services, as it seems like everyone and their brother has opened up some kind of "estate sale" business.
Once you talk to a couple places, they can give you an idea of the specifics: if they'd do it on-site or move everything, how much they estimate things would bring, etc. They could also give you an idea of a good time to have it. Auctions and estate sales seem to have a particular "season," and a lot of times I think you'll get more in the summer months rather than winter. Completely understand if the widow is in no hurry to sell. If she wants to wait til next year or something similar, maybe just help out by making sure the place is secure, heating and a/c works if installed, that sort of thing.
I am always leery of Craigslist / Facebook Marketplace / etc, or anything else that has people coming over one at a time. For one thing, it becomes a huge time sink to deal with all of that. Secondly, people can by nuts, crazy, criminal, etc.