re: gluing end grain

Here is an idea. You would have to make a safe jig though.
Glueing alone would be ok but I wouldn’t count on it being a heirloom. Eventually the joints are going to break with the wood movement. Not sure how you’re attaching the lamp section to the base but you might gain enough strength with that attachment.
Here’s the idea, as always just conceptual to give you food for thought.