I thought I would make the planing stop out of an oak log I have. I drew a 2 by 2 inch square one one end and chiseled away most of the waste to result in a 12 inch long stop. I used a jack plane to get down to the final dimensions. The top and bottom end of the stop was chamfered to prevent any chipping during use.
The 2 by 2 inch mortise was cut through bench top. I actually made the stop a little too skinny and it did not hold in the mortise. The fix was to glue a thin shim of wood into the hole and now it works as it should – with taps from a mallet.
T r i a l & E r r o r 
Very nice! Thank you for motivating me to get my planing stop installed. Loved the shim solution!