Round stock spins on a bolt mounted to the vertical piece, snug the chuck jaws to the round stock. Used a dead center to scribe the spindle height to the vertical for bolt hole location. Place the caddy on the ways, spin the chuck onto the lathe spindle. A vertical tube mounded to the base would provide a home for the chuck key. Still a dead lift onto or off the lathe, a jib crane would be nice if I had one and the room.
Used furniture wood nuts (3/8-16) to bolt the angle iron to the wood base.