This is pushing the edge of my knowledge and probably safety.  I tested the voltage in a few places on the board:

(I didn't control for polarity so I'm just listing voltages)

Disk Port Pins 7/8 - 12V

Pin 5 (the 5V) - Nothing

UK4/6 both 5V

UC8 - 12 V

C1 - 5V

C3 - 5V

C4 - 5V

C5 - 5V

C6 - 0.5V

C7 - 5V

C8 - 5V

C9 - Nothing

C11 - 5V

C12 - Nothing

C13 - Nothing

So unless "nothing" indicates bad trace wires/soldering pads and not busted capacitors, this definitely needs a recap.  The question is is that preventing the screen/ROM from engaging...?

I also pick up voltage (maybe a little less than 5V; at the moment I'm doing this somewhat manually - or digitally in the denotative sense...) at both the RAM and ROM, which is a tentatively good sign.

C9 and C13 are involved in Horizontal Sweep (C12 is also in that circuit - a dampener) I think.  So perhaps their failure prevents the screen from working.  However that shouldn't affect the ROM (?).  I'm concerned that recapping will just give me a blank albeit phosphorescent screen with no processor or ROM activity.