Think I may have found something, dumb luck. On another site found a post about "MOSFET's and the 148GTL". On page 3 was this interesting info:

A little info on removing TR24 in this chassis.DONT DO IT!

"Removing TR24 upsets the ALC and causes SSB distortion.
pioneer, I’m wondering if some of the distortion issues you had on SSB whenworking with your MOSFET mod might have been due to TR24 being gone.

To remove the AMC limiter in AM mode only, the transistor to remove is TR26.
I just remove R131 instead, and if you look at the schematic, you'll see it’sbasically the same thing."

Page 4 found this:
"The 148 effectively has two modulation limiters. One for AMcalled the AMC (automatic modulation control) and one for SSB called ALC(automatic level control). Each is controlled by one transistor on the board.There are many ways to disable the circuit from removing the individualtransistor to removing a resistor. The end result is the same.

I don't recommend disabling the SSB ALC circuit as this can cause moredistortion problems then disabling the AM AMC. The things to remember here areto keep your mic gain at the right setting. If you disable the AM limiter andkeep the mic gain under control, you will have a more natural sounding audioquality with higher modulation peaks.

Adjusting the AMC variable potentiometer for the maximum modulation setting isnot the same as disabling the circuit. Even at maximum modulation setting ofthe VR the limiter is still clamping the audio peaks. This may not be a badthing if you don't have access to a scope to find the setting that providesmaximum modulation without flat topping on positive peaks or worse yet, cuttingoff the carrier on negative peaks. This is the number 1 cause of adjacentchannel interference on CB."

Had to open mine back up. Sure enough TR24 was AWOL. Sitting adjacent to the vacant spot for TR24 the C208 was corroded/ eroded. We had guessed on a cap or two being bad. R131 had been clipped and cold soldiered back for some reason. It was standing straight up and down, not sure if that is factory or not. Service manual picture is not clear on that.

Now! If I just knew what the hell I was talking about.