Thank you jjss49.
It may sound strange but your criticism actually aligns with the mods for the 545 MKI. Select parts are upgraded with higher quality and some with new values as well.
Mods to:
Change to higher uf caps in the power supply
Change resistors and transistors in the input circuit to stabilize Offset Voltage
Upgrade the type and value of the Bias cap
Add shunt caps to increase the Low End and correct Phase Shift
Change select resistors and caps in the signal path with better quality components.
I'm not an engineer but I used to be a tech and still have a bench with a scope, load, freq counter, distortion meter, etc. What if any before and after tests would you or others recommend? I've read these mods which cost a few hundred dollars can transform this amp to compete with those costing thousands more. I'd like to see how this turns out.
Thank you for the input!