(Note: A Google search for a source for the subject handles also turned up a thread about them on the old board. It's probably a little late to help the OP of that thread, but I was so excited about finding a source, that I decided to post as a new thread here in case it could help someone else (original post on the old board is included at the bottom of this post). I have no connection to the two companies given as sources below - just providing the info. in case it will help someone.)
The following link is for Crane parts: http://www.deabath.com/Crane_Parts/crane_parts.htm
Scroll down to the last item on the page, and you'll see the exact handle asked about on the old board - called the "Drexel" model. These are reproductions - they actually appear to be made of better materials than the originals - so instead of lasting "only" 50 years, these may last 150! 8^) A little pricey, though, at $49.90 *each*! But probably cheaper than mat'l & labor for entirely new fixtures. One of my Drexel handles needs replacing due to exactly what they state (corrosion) - a Google search turned up that site.
They also have a repair kit that includes the handle adapters (the square pieces of plastic that adapt the handles to the stems) - though they are still available individually from places like PlumbMaster (800-523-5130) for reasonable prices.
Original post on old board - thread titled "crane faucet handles" (http://terrylove.com/wwwboard/messages2/34283.html)
: looking for faucet handles to crane sink from the 50s, they are mounted on sink that has taller center section than bowl, has flip lever to open/close drain, handles are round and are screw mounted in center