[Richard G]

Bidri is the black alloy, Bidriware is decorated bidri. This is normally done by inlaying silver gold or brass. To do this you need to cut into the bidri and force the decorative metal into the depression. Most bidriware is polished so that the surface of the bidri and the inlay are flush, but I understand Lucknow and Poona made bidriware where the inlay stood proud. I believe bidri hilts are out there but it is quite brittle and hence such hilts would be decorative only.
Koftgari is gold or silver laid onto another metal, almost invariably steel. This is done by hatching the surface of the steel and beating the silver or gold onto it so that the hatching grips the overlay. Usually gold or silver wire is used, but sheet is also possible. With skillful burnishing most of the hatching can be removed so that the result looks like an inlay. However using a loupe will often reveal traces of the hatching. As you can imagine it is also possible to combine both inlay and koftgari to various degrees, to the point where the distinction is decidedly blurred.
Hope this helps
Regards
Richard
PS. The believe the virtue of Bidri is that it does not corrode or taint water and so was used for huqqa bases etc.