I found some very cool links that will help in beating the game:

An excellent collection of maps for the game, with indications for items and screenshots:

https://vgmaps.de/maps/pc/elvira-mistress-of-the-dark.php


A list of all alchemical ingredients for spell making and also how many there are total:

https://www.nemmelheim.de/horrorsoft/elvira/files/spellbook/Spellbook.htm


A transcript of the hint book which includes some lore, a walthrough and the location of all ingredients:

https://www.lemonamiga.com/games/docs.php?id=550


Hope this helps.