With apologies for the delay: Current lead time for mutes is about 4 weeks, due to my many happy travels in playing recitals and with several orchestras, but this has put me a bit behind and I'm sorry for the added delay on my part. With thanks- Ilan 

...boy were my colleagues not into the mutes I liked, and I found the mutes they liked too unreliable.  Frustrated with the idea of having to use different mutes in different registers, or drilling out my mutes only to replace one set of problems with another, I decided to start fresh.