Stevem, thanks for the reply. I agree with your post and only mentioned the K150 because the board was pulled from a chassis marked as 4-150-1, serial # 15623. The chassis also has 5 chassis mounted T0-3s, of which 4 are driven as shown below.  

I haven't pulled anything yet, but 4 of the T0-3 drivers are driven as below:

  RCA 40409   RCA 40409   RCA 40410   RCA 40410  
       I           I           I           I
     T0-3         T0-3        T0-3       T0-3  

I plan to beta test all transistors, before any low voltage test since this board and the rest of the chassis had been idle for years.
Fwiw, I haven't seen the 40409s and their heatsinks since restoring an old Standel.

The thermal diode is also broken, so I may try locating a thermal diode from a Peavey heatsink.  

My last post was incorrect. The 4 output drivers are 2 40409 and 2 40410s.     

Here's an update on the K200 A-2 / 102 preamp boards.
After testing the ESRs, then replacing the bad caps with newer caps at a 50V rating from the stock I had on hand, they were bench tested using my bench power supply and Oscope. The transistors were previously beta tested and had no issues.  A little potentiometer cleaner is that was needed to complete the Preamp boards.

The original T0-3 Transistors have also been beta tested on the 702 board, but have since found closely matched 2N3055 replacements.  Caps still need to be tested and driver transistors as well.

I may prefer to have independent regulation on the + and - 34V sources. Most likely because I cannot successfully enlarge any of the drawings including the K200A-2. Print outs are either blocked or out of focus on the L and right sides of the drawing, making it unable to read most of the schematic.

It may be an printing issue on my side.  

BobW