We sell these Quick Release Bow Knuckles for $25. Same idea.
Personally, i don't find it that hard to remove the torx bolts, but I don't take my top totally off that often. (and I get a free supply of replacement bolts when I lose them, too!).
Homemade? I wouldn't think it would be that hard. Just keep in mind that when you drive at freeway speeds there is a LOT of downward pressure on those connections. Wind is HEAVY. So you need a nice tight fit that still rotates. A pin is fine, just make sure it's big enough to fit snugly, but not too tight.