Brahms Intermezzo in A major

Let's see if it'll let me post this this time...
This piece is in composite ternary form. It starts out in A major and at first has four symmetrical phrases that seem to make up a phrase group more than periods of some sort. After the phrases, there is a rather sudden modulation. The A section continues until the pickup to bar 49. The line before this contains an extra terminary phrase/cadential extension and then we have the B section. B is in binary form. There is a drastic drop in tempo in bar 57, along with a ritardando beforehand, switch to legato, and a dynamic marking of pianissimo, all of which set this section apart from the others. This lasts until bar 64 when it returns to a part similar to the one we were first introduced to in the B section as can be seen by the left hand's arpeggiations. The A section returns in bar 76 after a ritardando and decrescendo, and then there is a change in dynamic. It begins with the original motive from the beginning of the first A section but then changes into having more of a developmental function.