little help guys? Williams Mantle + story

[1880nonsports]

My friends brother-in-law recently passed away and left THOUSANDS of cards and even more memorabilia items. MANY of them are signed by Billy. Friends apparently with Billy Martin and obviously a fan - he left behind 4000/5000 Billy Martin cards and signed items. MAYBE 200+ Dodgers and Mets and assorted signed baseballs. Also a signed Mantle jersey and a signed Martin jersey as well as numerous signed auto racing jackets.
I'm NOT looking for a lot of free advice. I have been selling on eBay over 20 (!) years and my word is my bond. I'm not an autograph guy. I have helped quite a few people here on net54 and just looking for a couple of educated opinions about the following three pieces. I'm trying to determine if these few things are "right" before I even address the collection. I am always impressed by the threads I follow here and hope a couple of you will suggest - probably/likely real (without it in hand) or boy that's so not real. TY in advance.
friendly,
henry moses