They are called Lampshade Risers- not finials. (Finials are what goes on top of a lampshade riser). They are no longer carried at Home Depot (not in Ohio), but Lowe's has them. They are made by Angelo/Westinghouse/Prime Home Expressions, P/N: 41441 package of 2 1" risers.
The post and the base are threaded in a weird 1/4-27, but 1/4-28 works fine.
