Assuming the board inside is cell But as is would they buy it as cell phone? Or maybe eBay? Wanted to get some thoughts before I ripped the board out.

Depends on thr revision and i don't remember which is which. Some go cell class most are telco.
If the only issue is a broken screen... ebay is a good start and I'll post a few links to other buyers in a bit. A broken screen is easily replaceable by those who know how, so there's money there.
That said generation 1 /original/ aside any eink kindle prior to Pearl (gen 4) will in pristine condition net under 10-20 so if there's more than just the screen II would simply scrap it.

The following companies purchase phones, tablets, and e-readers. Many buy SOME devices that are broken, damaged, or dead.
maxback
IReTron
EcoATM
YouRenew
Abunda You'll need to call/email them for a quote.