Always happy to see someone who wants to preserve and share funeral cards. I maintain the funeral card collection for the St. Clair County (IL) Genealogical Society and would love to have you contribute images for any cards for folks connected to the county! Would love for you to send those to me at email@example.com
I'd suggest genealogical societies in relevant counties as a place to inquire and share cards.
Find A Grave is a great option assuming you know where people are buried since the images are tied to cemeteries. Not sure how it works otherwise, but happy to learn if I'm missing something there!
Thanks again for preserving and sharing these treasures.
Lisa Doussard Pleggge