I made a poor assumption that the 18″x19″ concord kettles that look identical to the spike 18″x19″ kettles would be the same dimensions.   I should have measured… thankfully it was too large and a few minutes with a dremel fixed it right up.  I made a cardboard template and used that to mark the excess I needed to remove.  A few (5) cut off disks later  and I am back in business.  I really like this false bottom.  Jaybird makes a great product and he can cut them to a custom sizes if you provide that information.  The welded on stand in the new design is very nice and acts as a secondary filter.