Re: http://i22.ebayimg.com/
I am not sure about the ambrosio version, but weinmann made a zillion of these rims in the 1960's and 1970's. I have a 1971 super course with mostly original parts, including weinmann dimpled rims. In 1973, my first ten speed went down a sewer grating on my maiden voyage, and my rear steel rim was replaced by a weinmann dimpled rim from the LBS.
Those rim disappeared from the raleigh line of bicycles in 1974, or rather, the dimples disappeared from those rims, to be more precise.
- Don Gillies
San Diego, CA