Yep, I have two of those exhaust pipe rounder-outer-thinga-ma-jobber-doers. I like any metal forming tool, where I can repurpose it for other applications. In this case, the red one somehow wont let go of its driving handle (almost like it is locked in with a circlip, but wont let go), but really there is no need for that handle version to be pulled out, you can "shrink" an out of round hole by driving the tool from the smaller end. You can see evidence of it being used to shrink something.
The silver (made in China) version, does have a reversible handle so you can expand or shrink depending on the direction of your whacking tool.
Going back to item "B", while the one end is clearly mashed on, the flat edge has been struck with a hammer for probably some alternative use, but only a few times. I "could" imagine those cones as being used for expanding/ shrinking exhaust pipe, but the ID/OD is much smaller and not typically found on autos.
I go back to my working theory of item "B" being seal drivers, and they "closely" approximate seal OD's used on older cars where they took the S2/S6 type bearings.