Goodman Games

I'd like to potentially run Temple of EE in DCC. I don't see DCC versions of them in the store however, am I missing them? Do these exist?

They do not exist.

OAR 1-6 are designed for 5e, and include the original versions as well (which would work decently with minimal effort for DCC).a

OAR 7 and 8 will have DCC versions.

OAR1-6 are licensed from WotC. If they would allow DCC conversions, rest assured Goodman Games would have already done it.

Has anyone ran adventures from previous versions of the game with minimal conversion, or even converted necessary mechanics on-the-fly during play?

How much hassle would it be? I've not tried it with D&D/AD&D to DCC, but I convert mechanics on-the-fly with everything from OD&D to 5e (except 4e - too much hassle!).

People Them With Monsters has a neat guide for creating monsters swiftly. If you have your HD, AC, movement rate, damage values, conversion won't be hard.

I found that there are spell conversion rules in Crawl zine #1.

My crib-notes:
1. non DCC spells use a different spell check: Roll d20 + Caster Level + INT or PER mod - armor check penalties.
2. Base DC 10 + Spell Level (x2)
3. Roll => DC = Success; consult the Spell Table Check Effects Table on p.20 (Crawl #1).

I playtested DCC using some old AD&D modules and currently run a lot of DCC modules using 5E, and in general I don't worry much about conversions. My plan is rarely to "balance" an adventure so my crew knows that if things go badly they should run away and maybe regroup. My rule of thumb is that in general DCC levels equate to roughly 2 D&D levels, so that gives me a decent idea of the difficulty of the adventure. If there is an equivalent monster in whichever edition I am running I may just use that, but otherwise I often just run the adventure the way it's written. I often double monster HP (or default to max HP for monsters) because PCs tend to be innovative and I typically run monsters without so much imagination, but if a monster is particularly clever it can be "as is" most of the time.