Properly wiring a Weston Vu meter bridge?

Hello, I have a quad vintage Weston VU meter bridge and I admittedly have never wired a VU before (therefore I am selling it).
Anyway's, I have someone who really wants these for there rig it but also has never wired a Weston Vu.

I've looked for schematic's without luck so I was wondering if anyone had any experiece wiring Weston Vu's and could give some basic insight into this? Thanks in advance

More closeup picture...

If they are connected to 600 ohm impedance line then put 3.6k ohm resistor in series with the high side of each meter.

Looking at the pic, there seems to be a + sign on the back, so can I assume that it needs an external bridge rectifire and 3K6 resistor?

The meter case was a stock item used for both AC and DC meters.

It is remotely possible it lacks a rectifier. Cheap "vu" meters don't. But it sure looks to be a classic VU Meter, which all had the rectifier built-in (designed for the right conductance).

It will be obvious. Without a rectifier, the needle will hang at the left peg, jittering on strong bass. To check, throw a 1N4007 in series, if it now works almost like it should, get a proper rectifier (not easy these days).