yes, you can use a 1000uF cap at C18.
i do.
when you remove C174, the negative lead of the 1000uF cap goes in the negative hole left by C174.
the positive lead of the cap goes to the base of TR41, which BTW, should be changed out to a 2N6487, or at least an NTE152.
change C172 to a 2200uF 35-50 volt cap.
i like to put R131 on a switch, but these days, i just remove TR26, and run the mic gain at 12 o'clock unless i need more for some reason. (never do)
change C46 to a .22uF monolithic cap.
replace the 2SC1419 (or 1135) in the power supply with a 2N6487, or NTE152.
replace the filter cap in the power supply with a 5600-6800uF 50volt cap.
as for the meter lights, just use white super bright LED's with a 470-680 ohm resistor.
if you buy 10-15 of the white LED's you can replace all of those lights, ON AIR, RECEIVE, etc...
i highly recommend replacing the electrolytics in the freq. counter if you have the skill (double sided, plated through PCB).
of course there are other mods, such as replacing TR14 with a 2SC2999, replacing TR19 with the 2SC1674 you just removed from TR14's spot, replacing diodes D1,2,21,22, with 1N6263's, or NTE583's. this will improve the receiver's and the noise blanker's function.
good luck with my favorite radio,
can you tell?LOL
loosecannon