There are several manufacturers that have used a carbon fiber sleeve connected to two aluminum or titanium flanges.

Nuke Proof?

Apparently their biggest issue was broken flanges, not a slipping sleeve.

If I was doing it I'd probably design it so your sleeve fits over the top of the hub spindle/shaft. Perhaps cut a square stop near the flanges on both ends.

As noted for the CF, a tight fit and epoxy should be fine. Especially if you have about 1 1/2 inches of overlap on both sides.

Getting them precisely true would be an issue, but perhaps not bad if you have quite a bit of overlap.

I'd probably first chuck up the uncut hub in your lathe, and clean up the center shaft before cutting (square, uniform thickness, stops on ends). Then cut, epoxy, and press back together with a properly sized tube of 6061 or 7xxx.

Give yourself just enough play that you don't bend anything when pressing together.

You might be able to weld, but some types of cast aluminum weld poorly, and it may well not be necessary, especially with lots of overlap and a good epoxy joint. Also, weld heat could be an issue.

Keep in mind that the two flanges are twisted 1/2 spoke to each other.

You could radial lace the NDS, but I'd probably just do the same cross pattern on both sides because of the potential of issues with radial lacing old hubs.