Well here's some stuff on eBay that you guys might be interested in:
Need a 175w merc lamp? Well here's some nice older and possibly vintage ones to stick in that lovely cobrahead of yours:
175w Westy 175w Sylvania Both are /DX full coaters.
Need a ballast?
Here's one with a starting bid of $20 (no bids as of posting) and also has free shipping to the US.
Some other interesting stuff:
LM Gumball Well it's technically a gumball but the refractor looks more like a lowbay refractor. A bit on the high side though.
OV-400 The rare OV-400 appears, missing the refractor though and a bit on the high side. Oddly it has a HX ballast which is rare to see in lights above 250w. Also it looks like the date code is "LG".
These empty cobraheads have also been on for a while.