I think the intro chords are Ab Bb G Ab Fm G (D or Bbmaj7/D.) I think the second chord of the verse is Gm, not D+. Also, D+ and Bb+ triads have the same notes; either works. What I think is happening in the bridge after "C'est la vie" is Eb G Ab Bb+, but there is a Bb note during that G major. It isn't an augmented chord, to my ears. Maybe a G7#9 would work there, but I think it sounds more like half the band played G and the other half played Gm.
"Theory only seems like rocket science when you don't know it. Once you understand it, it's more like plumbing!"~John McGann
There is no "A" anywhere in Lynyrd Skynyrd.
It's S Q U I E R! Not Squire. Look at your guitar!