Having given this a bit more thought I realized we need to extend this discussion to tools. Most owners will have quite a bit of money tied up in tools, so there has to be advice to the widow on how best to dispose of them. However, there are enough differences between them and parts or bikes that their disposal has its own issues.
Again, the assignment is to figure out what we can/should do now to ease the work and maximize the income of our widows later. It seems to me there are three categories of motorcycle-related tools in our garages, each of which might be best handled differently by a widow.
Tools widely available today: Metric and A/F socket sets, crescent wrenches, screwdrivers, etc.
I'm told that any yard sale that advertises "tools" draws a large number of men looking for bargains, so even a common set of metric spanners would quickly sell if priced right. But, are there other, better ways of selling "common" hand tools that don't attract a bunch of strange men to your widow's front yard?
As for what to do now to prepare for this eventuality, if you at least have your common hand tools in tool boxes with labeled drawers, it wouldn't take long to prepare a list by drawer (e.g. 'screwdrivers' drawer -- $1 ea. for most of the contents).
General purpose tools of interest to old car and motorcycle buffs: BSW spanners, BSW deep drive sockets, BA taps and dies, etc.
Here a yard sale wouldn't be best anyway, and instead the highest price as well as greatest good to humanity would be to offer them to a wide audience. Is eBay the best, or essentially the only reasonable, way to do this?
The same preparation for above would work here, although with a few more details (e.g. set of 1/4" BSW sockets, $25; set of BSW impact sockets, uncommon, $75, etc.).
Specialized and custom made tools: Specialty tools made from drawings in 'MPH', complete set of engine tools for a Triumph Trident, general purpose fork assembly tool, 250 lb. electromagnet for magnetos, heavy cast iron table with jigs and fixtures for straightening frames, etc.
OK, now it gets interesting. You spent 50 years acquiring and fabricating custom tools for the variety of bikes you've owned, and any number of others would/should die to get their hands on most of them. Some of these tools could be gathered into batches and offered on eBay (e.g. all the Trident tools; all the BSA tools; etc.), but is that best? Listing them individually might bring in more money, at the cost of a lot more work, but that would be the widow's decision of your advice to her was to go with eBay for tools of this type (which you've taken the time to list, or at least point to the drawer holding them, since otherwise how would she know what's what?).
But, what of the specialized tools you own that would be valuable to a much smaller range of people. I'll offer my custom-made 70,000+ A-turn electromagnet as an example. Few people even would know what it is (sadly, including quite a few magneto rebuilders), but those who do would know that it would be well worth the cost to ship the 250 lbs. since it easily would cost many thousands to make one of their own. So, where to advertize a specialized tool that for 99% of motorcyclists is only worth the scrap metal, but for the other 1% is quite valuable?
Less extreme than the electromagnet is I've made every specialty tool mentioned on the pages of 'MPH' over the past 50 years. On a yard sale table they might sell for 10 cents each as whim purchases, but they should be more attractive than that to many Vincent owners. So, along with a list of tools categorized as above, I should leave her contact information to place an ad in 'MPH' for the tools that are in the "Vincent" drawer of the tool box. That covers Vincent tools, but it's not obvious to me what to do about comparable BSA, Triumph, etc. ones, since I'm not a member of all those clubs, not to mention Amal, Lucas, and BTH specialty tools, since those don't even have clubs.
A notebook with annotated photographs clearly is needed so your widow can tell the difference between a Matchless hairspring valve compressor and a Vincent ESA spanner. But, beyond preparation work like that which we have to do ourselves ahead of time, what are the best ways for your widow to dispose of the specialized and custom made tools you've accumulated over the decades?