It seems 700 replacement lamps are fairly easy to source but they all appear to be car types.
The original lens had "motorcycle" cast into the glass and had a different diffuser pattern.
I find car types at swaps usually very cheaply and they are left dip types.
Usually there is no provision for a pilot light but that is easily fixed with a 5/8" or 16mm holesaw.
It is possible to prise the crimp around the glass open but not so easy to get it back without breaking the glass.
The reflector is not chrome plated but is silver plated, I have been told. Don't know why it doesn't tarnish if that's the case.
Another bit of trivia, motorcycle bulbs are constructed differently to car bulbs.
Motorcycle bulbs dip straight whereas car types dip to one side, depending on the side of the road on which it is driven.
Trev.