I don't think having a bookworm is modeling the character (unless multiple likenesses are used).
For me, to create original characters, I start with setting (before creating characters and plots). I just created a magic items database (think of horcruxes in Harry Potter). In it, I have 60 items. They are found in varying locations. They were created by various characters. They are owned by other characters. From the locations they are kept, who owns them, the mini quests or subplots needed to find them, and so on, I can create the characters I need to develop plot. I know the items are either harmful or helpful to the MC. I can develop my MC and my side characters, as well as monsters or other antagonistic forces preventing them from getting the items.
My characters fall in standard roles, such as: anti-hero; hero; antagonist; love interest; gatekeeper; and so on. However, I can develop unique attributes and quirks that suit the items owned, created, sought after, and so on.
As per the question, no; I have not modeled any of my characters after existing characters. I may develop them from inspiration, but not modeled a character with multiple likenesses of existing characters.
I'm a believer in making things original to where people will want to explore your interpretation of familiar things (settings, magic, other).