Arduino with enough PWM pins for the number of meters. RC filter for each meter with a time constant of the order of 0.1 seconds to get smooth movement, then direct to the meter coil. Adjust the total series resistance for full scale defection with a steady 5V output level. Its trivial enough not to even need a PCB apart from the arduino board, which should be bought without headers fitted so you can solder direct to it.
The Arduino Nano only has 6 PWM pins so if you have more than 6 cores you need another solution. I suggest Arduino Pro Mini, which doesn't have on-board USB to serial. Feed all the Arduino RX lines in parallel via the same USB <=> serial converter, and use a protocol that 'tags' each value with the core meter its for, e.g. a binary protocol consisting of a continuous byte stream of [0x80 | meter_address<<1 | (PWM_value & 1) ],[PWM_value>>1], Because the high bit is set for the first byte of each meter block, synchronisation is easy. Set the first meter address by grounding a pattern of spare digital inputs on each board so they can all run absolutely identical firmware.
That's the cheap and easy way to do it one-off. If you wish to mass produce them there are better options e.g. multi-channel LED driver chips with individual PWM dimming - just fit RC filters feeding meters instead of LEDs.