jeclif,
I don't have a 527 to look at for you, but, I did look in the Instruction manual for the 527, and it shows that the rear frame screw (part #70) is the only frame screw that has a spacer (part #68). The front frame screw (part #69) has NO spacer according to the diagram.
I was surprised to see this on the 527 because the 550 does have a spacer on each screw.
You can download a manual for the 527 at
http://www.cz-usa.com/support_downloads.php Note: It appears they (CZ) are having tech problems with their site as I type this message, so just keep trying if the link gives you an error message.