How to check for stylus wear?

I own a Sound Smith VPI Zephyr. I'm sure there's more than 1000 hours on it, and possibly even 2000 hours. How can I check the stylus for wear?? If, for discussion purposes, the stylus is worn, should I send it back to Peter Ledermann for re-tip? Any idea how much it costs and more importantly -- how long it takes to do?
Wow you must listen to alot of music. How long has the Zephyr been out?

You need a microscope with around 500x magnification and know what to look for. Are you experiencing sound degradation?

I think a SS retip is from $150 to $350 depending on which cantilever/tip you want. From what I read it can take some time to get a cart retipped as Peter is usually very busy.
Contact Peter. I wouldn't trust any other approach.
Dopogue -- agree 100%. Sarcher, I do listen to a lot of music. Unfortunately, I lost track of hours. To my ears, the Zephyr sounds ok. Problem is that a slow degredation is hard to detect. Fortunately, I have a DV 20Xs back up carty. If I send the Zephyr out, I won't be out of commission. But IMHO, the Xephyr sounds better than the DV.
Of course have Pete redo it. He's one of the best. And he made it to begin with. A no Brainer
I have a Zephyr too and have spoken to Peter about what I thought was a "low rider" issue. His suggestions included running the Zephyr's VTF at 1.4g on my 10.5i arm and raising the back end of the tonearm up to where it was no longer level but appeared slightly "downhill." I really like this cart.