I was recently sent this link from WelcomeHolmes, I think.  It seems that Dan Posnansky's extensive collection of Holmes/Doyle memorabilia is going up for auction in a week or so.  That's exciting in itself, but most (all) of the items are out of my reach.  However, the catalog is a free download in .pdf format or you can look at it on line and boy is it interesting!  Well worth the look in. 
Here is the link to a Wordpress article about it.  dinneratmarcinis.wordpress.com/2017/12/10/auction-the-sherlock-holmes-collection-of-dan-posnansky-a-little-freebie/

The download link is about 1/2 way down the page.