Have some old flasks (Stoddard,cornucopia,calabash, etc).
1. Are these considered authentic?
2. Ballpark idea of rarity/price range?
3. Can these be identified to any specific maker/mold?
All of the ones you posted photos of are authentic and vary in value from $70 or so for the majority of the ones you listed, maybe $120 for the Cornucopia, and maybe $200 or so for the double eagle. None of these are rare but generally they are fairly desirable.