Here is a
link to the newest version (8500). I can't find any reference to the 4600 though.
If my memory serves me, there was a lot of change going on when the original Escort (I had one) made my Cincinnati Microwave was discontinued and replaced by the Passport. The company name changed to Escort and the Passport became a model on the Escort line.
The Passport was the top of the line back then.