I finished the concrete slab with a fine grit sand and a light matte clear coat finish.  I also put a copper leaf marker on the surface where the charging pad is hidden; it's pretty hard to line it up right without it

I wiped the block  with danish oil and finished it with shellac. I put a little color tag thing on the bottom right corner- it started as a way to cover up a little crack in the veneer, but I actually thought it looked pretty good and stretched it halfway around the block