That is a rail, just not a standard one. You can get an adapter at Condors Flight or Your Gun Parts for $20 bucks or so that will let you mount a Weaver or Picatinny accessory.
I'll leave the "Why?" for someone else.
![Smile [:)]](/emoticons/emotion-1.gif)
Edit: Here's a link and the price went down too.
Junk Hanger Yes, it will fit the UC and Mini too.
You trying to screen for communists? Don't worry, we're all cool. - Dale