Note from Bytee!
Great idea, but this is a bit of a con.
"Conversions" do not account for number of attacks, resistances to spells or physical harm, countless special abilities and innate spells.
Check entries against listings at https://www.aonprd.com/Monsters.aspx and convert the missing to your system of choice. Or better yet, just use the original entries in the AD&D Monster Manual or the Basic Creature Catalog.