Welcome to CC and congrats on your future ERA!!
Here's a thread with some discussion about the Tri-ax (transmission thread that was sidetracked
).
Toploader vs TKO 600 Subjective Shift 'Feel' Rankings
I don't own an ERA, so the folks at ERA or someone here should be able to answer your questions about compatibility. I know that with the Superformance, the reproduction (dog leg) handle works with the Tri-ax.