Vintage mod dress

I just got this super cool vintage 60s 1960s dress and it’s a tiny bit too small for me so my loss is your gain! It needs a little bit of TLC — there are some smudges on the front and one of the bust dart seams is coming loose. Also missing part of the neckline fastener. I haven’t tried cleaning/repairing myself because I’m afraid of making anything worse. Best for size XS — i’m 34.5-26-36.5 and it pulls in the hips a bit. **some photos have been edited to make measuring tape more readable