The picks Lemmy uses on stage don't have any signature or Motorhead designs on them. They are generic purple or grey/black Dunlop 1.14mm max grip type. He uses double sided tape on them to keep them stuck to his fingers. He probably has a problem with dropping them.
The last MH gig i was at in 2011 Lemmy through out some picks at the end of the show. Those had a small Snaggletooth MH England on one side with a Lemmy signature on the other Dunlop make with silver holographic print. These one's here.
I've seen some new picks but i'm not sure if Lemmy is using these. As i have seen a signature type the same as this one here. Cool pick.