Steve Zarelli Space Authentication has published an online signature study focusing on Virgil "Gus" Grissom.
Included are a number of verified signature exemplars that span the short period Gus Grissom was signing autographs, as well as Autopens, secretarials, pre-prints and suspected forgeries.
In my estimation, Grissom is in the top five risky autographs of flown astronauts. Hopefully, you'll enjoy the study and it is of value to the community.
As always, comments and feedback are welcome and thank you for your support!