Most visitors online was 1660 , on 12 Dec 2020
It is a rare item probably because it cost $10US in 1950. Not many around. Watch Ebay and copies come up occasionally. I've seen prices from $100 to $50. It is worth whatever you pay, I use it all the time. There are specific categories by brand, by configuration etc. Sections on Chronographs. Make sure you get the original and not some brandX reproduction.I don't have that catalog either.