...Alright, I've really been on the fence about it, but the meteor finally won me over. As much as I love both designs, and Steph's works better with the stats, it seems more Steel monotype than part Ground. Pip's design works from a typing standpoint since every fossil Pokemon is Rock-type, and Steel/Ground are both effective against rock. Plus, I'm probably the second biggest paleo-enthusiast here next to HONK. At this point, I'm honestly fine with either outcome!
After mulling it over a lot, I changed my mind. (Sorry, Pip!) I think earthenware is more convincing for Ground than a meteor (e.g., Golurk vs. Minior), and Steph's design looks more likely to have a base 50 Attack stat. I still like both of them. :)