About to approach my next ability score improvement and I am debating where to take my character.  Here are the options I am considering:

1. Multiclass into a Wizard 
2. Take the Ritual Caster Feat (Wizard) 
3. Ignore my inspiration (see below) and just build the Sorcerer to max level based on my initial vision of the character. 

The campaign consists of Bard/Cleric, Druid, and Sorcerer for spell casting purposes.  The module we are playing has resulted in the party acquiring several scrolls, spell books, and grimoires that contain spells that tend to only be on the Wizard’s spell list. Now we can trade some of these items when we return to civilization, but they are assets that are becoming a waste.

At first, I was looking into scribing scrolls. Thematically this works for my character (he is an academic) but that only helps for spell scrolls on the sorcerer list. That lead me to considering the Ritual Caster (Wizard) to at least capture the ritual spells we find. But then I thought, taking a small dip into Wizard (character has the stats for multiclassing) would offer an option to take advantage these items that hold Wizard spells. 

Finally, I thought I might just be overthinking this. If this campaign goes to level 17 or higher, I am giving up access to a 9th level spell.  Is that trade off worth it so my character can access more spell options earlier in campaign?  I haven’t seen too many instances in which the party wouldn’t have struggled if we had access to a Wizard’s spell scroll. 

In summary, do I invest in a character build that can use these items with Wizard’s spells, or do I stay on the course and max out my class?

Thanks for the input

So, a small dip for Wizard won't do much for your ability to scribe spells; you'll only be able to scribe ones you could learn at your Wizard level. Ritual Caster is probably your best bet, although I would also suggest talking to your DM if you feel you're being shorted by finding things you can't use, like the grimoires.

If the module you are playing strongly benefits wizardry, I would ask your DM if they can use some DM magic to weave the loot into something more useful. Alternatively, I would ask to respec. As a wizard. If you want the metamagic, you can benefit far more with a dip into sorcerer than a dip into wizard, though the feat metamagic adept is a staple for wizards. Your second option to take the ritual caster feat is a good option too. Whatever you do though, avoid dipping wizard. Too many better options out there to get what you are after. 

A dip into evocation wizard could be nice, since you get a limited but free form of careful spell