I'm not Lee, but strength-wise a thin-wall hollow tube should be fine, and much lighter.
Something that slips neatly over what you have, with 1/32" walls "feels" right to me, if it's made out of a decent high-strength alloy (2024? I'm not sure what's available in tubes). It'd probably work to epoxy it on if you used the right glue (meaning: not what's on your model airplane workbench). Bigger diameter would be better, probably up to 1/2" OD, if you don't mind throwing away what you have and starting from scratch.
You'll still have the weight of the bearing, fittings and prop -- you may find that the prop hanging out back there is as much of an issue as anything else.