jwmmakerofmusic, are you sure that you are looking for exactly belladonna scent? I find it hard to believe what belladonna would be the main note. Even synthetic, I know the plant, and today try Fame. I don't want to disappoint you, but if you want make something good, don't believe official descriptions and notes. Read about perfume making and work with you nose... Belladonna - beautiful, attractiv part of legend, this dangerous plant fits nicely with Lady Gaga image and alchemical black perfume color. This is marketing.
It seems to me that you're looking for Lilly of the valley, or Convallia. Another poisonous plant, substituted by synthetic aromachems, and I think this perfume really contain traces of it.
In three words - very sweet heavy floral, more sweet than heavy. Light/sweet version of Alien or so. You need jasminum sambac, or/and if possible and you can find where you live - very similar to all perfume scent Motiya attar. In top I find traces of pink pepper, and very carefully, moderately I will use Palmarosa var. Motia if I want to create something like Fame. I am not a prof, and more familiar only with naturals. Maybe Syringa vulgaris CO2 can be useful. If you planning use synthetics, someone else here can help better. In Jean-Claude Elenna "Diary of a nose" i find "berry" suggestions: raspberry - fructone, beta ionone, frambinone. In Fame more likely that are something like blackberry, but some form, natural or no source of ionones you need anyway. For sweetness - vanilla or vanillin. Perfum not long-lasting, and If contain some musk, maybe it can be traces of Romandolide, but again, very small quantity. I think you know that perfumes contain many more ingredients than listed in promotional descriptions. You can't recreate Fame from a 5-7 published parts; yoou need dozens or hundreds. But - good luck!