"Morris" key (5): Boring the return spring recess with homebrew faceplate

In order to turn the recess that seats the return spring I had to devise a way of mounting the base onto the lathe in order to bore it out.  I drilled four holes in the back of a 3/4" thick disc for the 4-jaw chuck to have a purchase on it.  Once it was mounted on the lathe I leveled off the faceplate with a couple of passes of the cutting tool.  

 I then screwed the base onto the faceplate after centering it to the boring tool.  The streak across the base is where I forgot to manually turn the chuck to see it it interfered with anything.  And sure enough it did.  The carriage caught one of the screws used to mount the base and subsequently pulled the tool into the work.  Now it has a decorative element that is quite lovely,... Don't you think? It should buff out. :)