I have no experience with Fords since 1982, but I will take a WAG here. Motorcraft is the aftermarket division of Ford similar to ACDelco is to GM. Motorcraft may or may not be equivalent to OE. Often they are not. I am going to guess that Motorcraft has several different lines (good, better, best,) just like everyone else. The BRF901 seems to be U.S. made. The BR1258C shows up as organic pads and on some sites China/Mexico made(maybe their budget offering?). bt4z2001b shows up as a Lincoln part number in my search.
The number 1258 shows up in the majority of aftermarket searches - Raybestos, Akebono, Wagner, ACDelco, AA, Autozone, etc.. And, there only seems to be one available design at these aftermarket sites, with two to three quality levels. I imagine all of the numbers you found will fit, there are just different numbering systems, not different basic designs. They all will fit your caliper. Just my hunch.