Its great to see some awareness of the importance of planning for the disposition of ones collection. Not only will such planning help our loved ones at a difficult time (if you've died), but if properly done, it will help to maximize the realized value of the collection, if that is a goal.
I have little doubt that each of us highly values our collections, and not necessarily in a pecuniary sense. If objectively compared to other collections Ive seen, my library is certainly nothing to crow about, but I have items which I consider priceless because of how they were acquired, their associations with certain people, etc. I know many collectors who feel the same way about their collections. But when it comes to the subject of donating ones collection to a legitimate museum or some other institution, there are very few private collections in existence today which would merit even a whiff of interest from such institutions. Thats just the cold reality of things. For people who think that they can simply bequeath their collections to an institution, its not that simple and easy, and they should do some extensive homework well in advance of the contemplated timing for a donation. Chances are great that even in the extremely rare circumstance where an institution is willing to accept a collection, it will not make any promises about the availability, use or display of your material. Odds are that your material will be shut up in storage, and to add insult to injury, its a near certainty that you will be required to leave a substantial endowment to pay for that storage in perpetuity or until the institution decides to sell your collection.
Nearly all of the truly rare, iconic and important conjuring books are either already well represented in existing institutional libraries, or they only exist in such institutions (i.e., all or nearly all copies of such books are no longer owned privately). The cold hard reality is that even if you own a collection of 5,000 magic books and magazines, the nearly insurmountable odds are that it is worthless as a museum-worthy collection.
For those who own apparatus, props, and wardrobes, unless such items (1) were owned by one of a tiny group of truly famous and important magicians (e.g., Robert-Houdin, Houdini) and (2) the items themselves relate to one of the magicians signature tricks or a historically-important performance and (3) the provenance of such items is well documented and undeniable, again youll find precious little interest from bone-fide institutions. And a word on provenance: the mere claim, without more, in an auction or dealers catalog that such-and-such trick or prop was owned by so-and-so is not well documented provenance in fact, theres no provenance at all with such a bald claim.
The sad bottom line is that, while magic may be super important to us, it is at or near the bottom of an institutions acquisitions desiderata.