How Can I Find Out Which President Silhouettes These Are?

I found these two old pictures of Presidents in storage, that were probably from the late 1800s or early 1900s.  How can I find out who they are?  I uploaded them to Google Images, but no luck.

the second one may be this: https://www.ebay.com/itm/192878507347

or https://www.brooklynmuseum.org/opencollection/objects/54752

Google "Kellogg Silhouette", there's a lot of similar images (not all are presidents)

Identical Kellogg silhouettes were included in this auction lot:

https://caseantiques.com/item/lot-699-5-kellogg-lithograph-silhouettes/

I believe the top one is Richard Mentor Johnson, who was Van Buren’s vice president, and the bottom one Levi Woodbury, a governor, senator and Supreme Court justice from New Hampshire.

Thanks, RIL and David Schmidt! Very impressive, how were you able to do such an outstanding job in tracking them down? Do you think the ones I have are original lithographs from the set, or imitation copies? 

I was curious so I googled the image along with some keywords, and got lucky. I don't know anything about determining the provenance of the lithos, sorry.

Ril did the hard part in coming up with Kellogg.

I don’t know about lithos, either, but my past life as an Antiques Roadshow viewer makes me think the trimming into ovals might limit their value.