1960s Lilli Ann Coat and Dress Set - How should I clean it and treat stains?

congratulations, what a gorgeous set!! and by Lilli Ann no less!!

cigarette odors can often be lightened if not eliminated by hanging outside, let Mother Nature air her out. It might take a few days (bring in the house in the evenings, of course) but that should help quite a bit.

I would be hesitant to soak that, instead maybe try rolling up a white towel and place it under those spots, and then spot clean (sounds like you're familiar with cleaning already). let it rest, and then maybe spot clean again, if needed. just be sure to have that towel underneath to help soak up any stain that may soak through rather than lift out.

I'm sure others will chime in with ideas for you here, too.

it is super cute, congratulations!