According to Larry Pina (1990) Appendix C/D/E pages 333, 340, 344, the 157-0042B will replace all of the earlier models including the -0026, for the Macintosh Analog Board US Version, International Version, and on the Macintosh SE Analog Board (used on SE and SE/30). Pina's subsequent 1993 book page 55 mentions that flyback failure with -0042B and -0042C is relatively rare. So best I can tell from Pina, either the B or C part are excellent for repair purposes.
If you should decide to do a replacement, consider carefully Pina's recommendations to replace the switching transistor and the discrete diodes that connect directly to the flyback, to avoid the possible quick death of the replacement flyback :disapprove: when you apply power!
The 157-0047-A is another kind of part altogether, for which the answer is no. I believe it is a power transformer used on the International Version only, Pina (1990) page 340.
If you should decide to do a replacement, consider carefully Pina's recommendations to replace the switching transistor and the discrete diodes that connect directly to the flyback, to avoid the possible quick death of the replacement flyback :disapprove: when you apply power!
The 157-0047-A is another kind of part altogether, for which the answer is no. I believe it is a power transformer used on the International Version only, Pina (1990) page 340.