I would replace that Solen, yes. You do not need to replace the other 2K resistor, as I said before, these are almost entirely out of the signal path.
I would do the least possible amount of messing around until you get the amp up and running properly again. If you go to put the 0.1uF Solen caps on the regulator board and that modification causes new problems, it will make debugging a lot more difficult.