Tubeless tires on old wire wheels would be a very poor idea. Wire wheels would require tubes and wheel liners to protect the tube from the spokes.
Sheldon,
Pursuant to V8COOPMAN's comment and my own thinking, I assume that the only reason you sealed the spoke welds on the rims was to prevent leakage of air around any spoke weld that was not air tight, correct? Obviously it wasn't to protect an inner tube given that you did not use inner tubes.