One Sided 1851 Large Cent

Need pics but sounds sanded down.

Heard of it...no. We would need some images to provide any sort of helpful reply.

Over the years, I've seen many a planed down copper, not to mention other denominations. Quite often, this was done to prepare the surface for an engraving or even a counterstamp. The coin's reverse is most likely the side that's planed down. Among my copper curiosities rests an 1857 large cent with a planed, blank reverse. These were likely the products of machinists, who typically were Masons. In studying counterstamps, I've found that many machinists counterstamped large cents and tended to avoid using other coins. Also, these machinists can be found among the Masonic rolls in their geographic area. Then too, these planed large cents were often used to make Masonic Pennies. It may well be that the blank ones we see nowadays were fraternal pennies that were never completed.

Maybe someone was doing a very light dusting of the coin?

If the coin shows wear the smooth side shows even wear I would guess someone prepped it to be a love token and never engraved it and carried it as a pocket piece and the smooth side worn enough to take off the grind marks.