Hello All Tool Buffs,
I found a couple of YouTube videos that show different Lasting Pliers/Pincers in operation. It starts by showing skiving (thinning leather) and then  at the  1:00 minute mark it shows the operation of very similar pliers/pincers to the original post. Looks like a very well designed tool for a specific job.
Toepuff & Lasting - YouTube
Kind Regards
Lionel