Interesting light. Not common to see 125w mercury used in North America, except in Eastern Canada and in those odd Regent yard lights in the States. I can't decide if that fixture looks like a tiny gumball stuck in an oversized head, or a tiny version of a high mast light. Those EYE lamps are good quality.
Nice find!, you would think that these were remote ballasted. 125w mercury saw some use in Canada, older mercury outdoor lights were sometimes 125w. The MTO also used to use 125w mercs to light highway signs,
The newer 125w mercs have a thin arctube like the 100w lamps so I guess those dimmed out pretty quickly but the older ones hava similar arctube as a 175w lamp, those would have probably lasted longer.