MJD posted this one on facebook this morning.. A plane for lifting slivers of wood to allow putting in nails "blind" by gluing the sliver back down over the nail head.
A somewhat more contemporary approach (no longer for sale...) that it looks like you could pretty easily re-create in your shop:
I've done basically the same idea as the LV tool with just a chisel which practically speaking works quite well most of the time if you pay attention to the grain (and the grain isn't to squirrelly). I'm not really convinced of the utility of a specialized plane for this, but thought it was a pretty cool device nevertheless.
Picture preserved locally for posterity.