What about the PC 3270 ones?
I'm not an IBM guru so this could be totally off -
My understanding is the number "3270" represents a category of terminal (cross-compatible ones it seems) and so the 3270 PC was an XT equipped to emulate (via hardware, basically the contents of the terminal stuffed in ISA slots) any one of the "3270 series of terminals".
As I understand it - which could easily be wrong - the aforementioned "3270 series" is what we're talking about when we talk about conversion-capable terminal keyboards.
Short answer: yeah, it's compatible. Keep in mind that it is a real terminal keyboard, not an emulation product...the cards in the computer and software/firmware provide the emulation.
Edit:
Wikipedia solves everything.
I was on the right track, but see the article for the differences.