To add a little more on the metering issue; I've built a couple of units with VU meters.
This is a VU meter:
This is NOT a VU meter:
Nor are these:
My most recent one uses VU meters:
I've built others using a single VU meter. Then it becomes an issue of WHAT you want the meter(s) to display. -You haven't said much, just that you don't like what you have at the moment. -It's extremely unlikely that there's anything wrong with the meter circuitry, so you'd have to give us a clue as to what aspect of the metering that you aren't satisfied with. -Would you rather have a meter that displays similarly to an 1176/LA4/Fairchild where it rests at 0VU and works its way "downward"? -Would you rather meter signal level? Should it be peak-reading? RMS? -Switchable? Should it be the sum of the left an right signals , or switchable left-right, or "greater-of"?
Without a description of what you don't like, neither I nor anyone else can offer any kind of insights or suggestions beyond random guessing.
The unit pictured above has two VU meters which can be switched three ways to display input level, gain reduction or output level. Three LEDs inset into the meter scales indicate input, output or 'VCA' (for gain reduction at the VCA) and there's also an RMS/Peak switch which operates in input and output modes, together with a fourth LED nestled in the meter scales, which shows whether the meter is displaying RMS or peak level. (Peak display mode is disabled in 'VCA' position, and the button and meter LEDs are inhibited in this mode).
A previous one which I built some years ago looks like this:
This uses only a single meter, and simply switches between gain reduction and a mono sum of the stereo output (-6dB, to keep things on-scale).
Now.... on the subject of
NON-VU-style GR metering, I've built and worked on units which have used many types of milliammeter. Here's a few I compared side-by-side:
Front:
Rear:
The left one is a GE, the other three are Sifam. The second from the left is a PPM14, and I think may be what you have... the two on the right are right-reading and left-reading Director models. These are the ones which SSL always used to use until they went out of production... then they switched to the less-expensive PPM14 (note the rather smaller motor housing). Both work well enough. -I've also used the 'Nissei' style meters which work adequately, although they're slightly nonlinear in their deflection response; but I seem to be the only person who ever mentions this, and even I don't have a significant issue with it.
So the world is your oyster; you can do whatever you dream, but you have to say what you want to do.