Nusach for silent Amida when chazzan in an other-nusach congregation

Question

My understanding (based, if I recall correctly, on R' Moshe Feinstein) is that when I pray in a congregation that uses a different version of the prayers (nusach) from the one I usually use, I should use the congregation's nusach whenever it's readily apparent to people around me which nusach I'm using (e.g. parts which are said aloud), but I may use my own nusach when I can do so unobtrusively (e.g. the silent Amida).

What if I'm leading the prayers? Clearly, for nearly everything, I'd use the congregation's nusach, but what about for the silent Amida, which is, of course, purely silent and presumably private? Is the rule different for prayers that include a repetition of the Amida (morning and afternoon) and for prayers that don't (night)?

Answer 1

Rav Moshe in the teshuvah you cite says

"And if on is the Sheliach Tzibur one must say according to the Nusach of the congregation even in his silent prayer since he is to order his prayers. " Igros Moshe O.C. Vol. 4, 33

I will try to supplement, since I believe there are those (such as the Divrei Yechezkel) who disagree.

Answer 2

According to Reb Moshe Feinstein, (I'll track down the exact Teshuvah when I get back from my trip) if one is the Shaliah Tzibbur, since the purpose of his silent Amidah is to prepare for the loud Hazarah, the S"T should use only the Nusah of the congregation even for his silent Amidah. Rav Elyashiv argues.