Making a new mounting board/table for the lathe and extension to sit on:
In the image above you can see it setting on a 2x10 pine board and I could use that, but the board has some twist and even if it is run through my planer to make both top and bottom flat and parallel, it would over time likely warp again. So, in the following photos you'll see the new table starting to take shape.
I'll be using three strips of 1/2 inch plywood glued and screwed together to make the new table, giving me a table that is 1 1/2 inches thick and will be less prone to warping than the pine boards are.
Here the three 1/2 inch plys are glued and screwed together, with the aid of some clamps. The new table board will need to sit overnight so that the glue can cure and then tomorrow the edges and ends can be trimmed down to the final form.
In this image you can see the existing table:
And in this last image you can see the lathe when it was still sitting on the board and it shows that it would be way to short for the lathe and the new extension to land on.