I moved the scope card into the HP 16500C mainframe and set everything back up. The screen shot below shows both scopes recognized by the mainframe unit.
The next thing I did was make sure that the scope cards worked, so I hooked up the function generator and did some simple tests. First with just the 250 MHz scope, then with both the 500 MHz and 250 MHz scopes together in a group run.
This is great, now I can look at up to 4 Analog signals at the same time on the mainframe.