Vintage DC Amps / Voltmeter Aircraft Combination Dash Gauge
Might be from an aircraft - Combination DC Voltmeter and Ammeter, MS 18098, unspecified manufacturer. Indicates Amps 0-450, Volts 10-35. Each scale has an adjustable 'max' pointer. The instrument was used on a number of Vietnam-era aircraft, including the Douglas A-3 Skywarrior.
Very clean and will make a nice display piece or use on a rat rod project