yeah I agree I'm going to keep the fixture 100 % original. The capacitor does have spade terminals four in fact. one (red) wire from it goes to the wire connector and a white wire exits this connector and goes to the bulb socket. the other wire (also red) goes to one of the spade terminals on the ballast.   the other two spade terminals on the capacitor are   connected by a short piece of bare fine wire (acting as a jumper) with a small inline resistor in the middle of this fine wire. this fine wire is soldered in place on both terminals. I checked several places online but 125 watt mercury vapor bulbs seem to be hard to find! lots of 75, 100 and 175 but no 125's also the base of the bulb must be standard size, not mogul. I would like to purchase a brand new bulb for it for maximum brightness but, like I say, they seem to be rare. would a 175 watt standard base bulb work?   

You probably got yourself a pretty rare fixture. Look on the Philips website and see if you can order them, I seen medium based Philips 125w bulbs. The reason this is CWA is because the low wattage bulbs don't produce as much heat as 175w ones, which is a common NEMA wattage. I have 2 inches of snow on my NEMA of 100w CWA and it didn't melt. If I put the 175e ballast in it, then the snow would've melted.

Since this fixture is kind of rare like you were saying, I guess finding a shade (refractor) for it would be almost impossible eh? I'll check the Phillips website for a bulb hopefully they have one.

You could use a standard NEMA lens assembly. Does the head have two latches on the side.

 the fixture has a hinged ring that slips over the shade with one latch.

A standard nema lens should fit then.

do you know where I could find one? I'll take some measurements to confirm the exact size.

Maybe with luck on eBay. The diameter of plastic shade should be 12 inches at the top diameter where it connected to the reflector.