by the fourth phrase of Theme 1 we've finally recapitulated to the appropriate thematic idea in the appropriate key. Kyle Gann has blogged about Clementi playing games with expectations about recapitulation in terms of theme and tonal region over at Post Classic but we're not going to link to that at the moment.
What we're going to get to is the non-modulating transition, which is where the sonata form can be what it is. We see that basically what held in the exposition holds here, the transition was a modulating transition in the sense that it got us from the key region of Theme 1 to Theme 2, but it didn't do this by starting in that first key but by jumping into the new key with both feet and finding ways to reaffirm it through secondary dominant and subdominant functions.
What is new here, and which invites a comparison to Haydn's brilliant Op. 76, 1 quartet, is how the recapitulation features a metrical shift. Matiegka's rising scale-work, in danger of being pedestrian if repeated too literally, breaks the duple meter pulse of the sonata so far and gets into triple meter in measures 125-127
Matiegka rounds off this sonata with a recapitulation of his opening theme, which was good, because his theme 2 was too slight to have counted as a formal finish and his I-V flourish pattern, though fairly typical for a guitarist-composer, is really the kind of passage-work that pushes forward to something else. He needed a something else to push forward to and that turned out to be, logically enough, closing the form with the idea he started it with.