By using just the slot and not an adapter I made a much thinner card assembly. Don't drink too much caffeine when attempting soldering like this.

This time I stuck in a cartridge slot, though it was kind of a pain to do and made me realize why I didn't the first time. I used, well, most of an IDE cable and wired it on the bottom of the motherboard. This is on the opposite side of the CompactFlash. The thinner the better.

Since then I have also learned more about CompactFlash cards, specifically that the wire up just like an IDE hard drive. Thus, an "IDE to CompactFlash" adapter is pointless. So I wired everything directly to a CompactFlash slot, as shown below. Coincidently, this slot came off the TV I used for the last Atari laptop.