Here is probably the best explaination I have had about the different versions of the 2950, make sure you read it !!
I hope this helps you one day, I spent much time figuring this out and creating this mod to be easy to understand for anyone.
The weak solderer should not attempt this as they could smoke the CPU if not VERY careful.
Also, you need to change what you are calling each type of RCI,there are NO old 2950DX models. (I'm pretty sure).
There are old RCI's with the red displays, (three generations of these to be exact).
Version 1 has the onboard battery for the memory and has to switch from CB band to frequencies by using the LOCK button.
The second generation unit will have the battery eliminated, and still has the large capacitor right in the way of the bracket knob mounting hole on the right side, problem there is someone gets aftermarket knobs and they are too long and bend the cap over till it shorts out or breaks the solder loose on the board. This radio is also where they began using the MAN button to change from CB mode to frequency mode.
The third generation they fixed a few of the interior flaws, such as the large capacitor problem.
Then the modifiable 2950dx, and the "Blue Dot" 2950dx which is the non modifiable version.
Easiest way of identification on these is the green display and they actually say 2950DX right on them.
The DX is also modifiable to seven megs, play around with the jumper settings, you will be amazed what this radio appears to be able to do. I have yet to put a 40 meter capable antenna on this unit to see if it actually works there or not, I do know that it keys there and seems to pick up static there too.