Just different pinout; no passive swaps so far.
Will do some measurements in the coming weeks to check that all current sources have the right outputs, etc, but I don't expect any big surprises. JoaMat has run 1220/2690 replacement editions of his T2:s for a long time without issue as far as I know, and the tra/ttc004 pair seems quite on par with that combo.
Measured breakdown voltage in the units I have is around 210V (rated 160V), compared to about 230V for 79/216 (rated 200V) if I remember correctly from somewhere in this thread, so not quite the same but close.