- G#-B-D-F# (fi-la-do-mi = (vii7)/A (dominant of D relative key of b- minor)
but resolving to
- G#-B-D-E# = fi-la-do-ri (1. inversion of E#-G#-B-D (ri-fi-la-do (VII dim7) to F#
(whereby the F# of the 1. tetrad can be considered as a sustained note of the following dim7 chord.)
The next chord in question is as you say again a augmented German sixth (inversion!) resolving into the tonic.
(In German this is called übermassiger Quint-Sext-Akkord that means augmented Sixth - with a natural fifth)
I’ll post here the important content of the link in my answer to your earlier question:
Tchaikovsky considered the augmented sixth chords to be altered dominant chords. He described the augmented sixth chords to be inversions of the diminished triad and of dominant and diminished seventh chords with a lowered second degree (♭scale degree 2), and accordingly resolving into the tonic. He notes that, "some theorists insist upon [augmented sixth chord's] resolution not into the tonic but into the dominant triad, and regard them as being erected not on the altered 2nd degree, but on the altered 6th degree in major and on the natural 6th degree in minor", yet calls this view, "fallacious", insisting that a, "chord of the augmented sixth on the 6th degree is nothing else than a modulatory degression into the key of the dominant".
You should really read what's said about inversions of the augmented sixth chord then you will probably see that my answer was fully applicable:
Augmented sixth chords are occasionally used with a different chord member in the bass. Since there is no consensus among theorists that they are in root position in their normal form, the word "inversion" isn't necessarily accurate, but is found in some textbooks, nonetheless. Sometimes, "inverted" augmented sixth chords occur as a product of voice leading.