Can You Identify These Night Vision Goggles?

Trying to ID this pair of NVG’s I recently acquired. All I know is they must be British or US as they are marked with English writing (“OFF”) etc. No ref. nos seem to be visible at all. Are they aircrew or army? Must be military of some sort.

The don’t work even with a new C-type battery. Anyone know where I could get them repaired?

Many thanks for any help.