Listing of Vet Free Agent Kick/Punt Returners
It's pretty thin, but there are guys there that could be of interest. Frankly, I think Asa Jackson will prove to be more than enough, but for conversation's sake...
Johnnie Lee Higgins
So, it's really slim pickings anyway. Out of those guys Crayton or Logan are probably the most accomplished punt/kick returners.
Disclaimer: The content posted is of my own opinion.