Thought more about moving the rear bearing block back. Rather that simply moving the CNCRouterParts bearing, I made another block so that I could use one of the extra tapered roller bearings to put the lead screw under some tension. Also the bearing can "float" to precisely align with the lead screw. The first photo shows the bearing block with the tapered roller bearing installed. Used an 8020 drop-in nut and a long set screw so no hole drilling was required. I still need to remove the original CNCRouterParts bearing. This should give another inch of Y axis travel.
The second two photos show some work I've done with the machine. Two more plaques and a lens holder to replace one I made nearly 20 years ago which has a failing catch.