I believe they were made from 1990 to 1994 then again in 1996.
I dont think they are as rare as the PWH or 777GR.
I was going to buy a UV7BK but instead, I bought a PWH which the serial #is 910760
meaning its a 91 model. I think the BKs are numbered like that too.
Well, the serials that start with #00 were the first ones made. Later that year they went to #900000. They are both made in 1990, but the #00 came first. Also, the Edge 7 trem was only used this year. Some of the late 1990's had the Lo Pro Edge 7.