With the drill press turning and the grinder spining it was easy to true up and bevel the red washers.
The bevel is a bade picture but you get the idea.
Next was spray 3M Super 77 and apply and trim the 1/2" closed cell foam. The whole base was sprayed, then the red washers were added around the bolt heads, sprayed the tops of the red washers then added the foam.
Trimmed with sharp knife and sprayed some semi flat paint around the edge.