HP Agilent spectrum analyzers - where is the chart with model numbers

[Merlysys]

I am looking into experimenting with spectrum analyzers that can do at least upto 2.9Ghz.

I thought higher the model number the higher the GHz, but I now see they are generation based too.

Here are the 8560 series. What hardware boards/sections do they share? Maybe not all models but some of them perhaps.
8560E  30 Hz - 2.9 GHz
8561E  30 Hz - 6.5 GHz
8562E  30 Hz - 13.2 GHz
8563E  30 Hz - 26.5 GHz
8564E  30 Hz - 40 GHz
8565E  30 Hz - 50 GHz