Wow so much stuff, so little time! Now, my biased two-cents.
You know what your engines are worth if sold, for instance,
on EBAY. Same for auction houses, though the amount to the
seller will be a bit less. It occurrs to me that it might be
worthwhile finding a person in your area with a good knowledge
of the values-at-sale time of these items, just to be sure.
If you go with an auction house, research their past and current
practices with a fine-toothed comb. One good thing about auction
houses - they do all the work.
Keep in mind, if you were to donate all or a significant portion
of your collection to a museum they will insist upon the right to
sell any parts they do not anticipate considering for display or
needed for research. You will, however get a tax write-off of some sort.
My opinions need to be tempered with the fact that I would love
to get a chance at several of the items pictured. I wonder about
the prizes you haven't shown.
Good luck,
Wayne