Can I attach these square-mount rails on my round-mount rack? (re: Norco RL-26 rails)

[sofakng]

I've purchased the Norco RL-26 rackmount rails a long time ago to use with my Norco RPC-4220 4U case.

The rack I've been using has round holes and I use network rack clip nuts to attach all of my equipment but these rails seem impossible:

http://imgur.com/qKWAgGj

Does anybody have any ideas or are these rails unusuable?

 

[JSchuricht]

The pics are lacking a few angles but it looks like the cage on the back of the rail ears could be removed perhaps by drilling some rivets out. Then you could cut the hooks off and drill a couple of holes for screws to pass through.