The gimbal system says its a space or vertical gyro and it doesn't have the extra gimbal that would give it the full six degrees of freedom required to allow manouevers beyond and through the vertical - as in a master reference gyro. Spinning it up would be safe enough as long as you leave it mounted in the gimbals. Most of the military gyros I've worked with were painted black and they would have either (a) for British use - the arrow symbol with a stores Section/Ref number e.g. 6A/XXXX or 6B/YYYY or (b) for U.S. or NATO, a Federal Stock Number e.g. 6445-XXXX-YYYY on them somewhere.
Ah, those white coated days in the instrument calibration laboratory, gently toppling gyros to measure erection rates on the test platform, come back to me. Then I wake up screaming...