Welcome to the wonderful world of no rear sights for the 527M. I have the exact same carbine, same caliber, and the only way I was able to replace my fixed rear sight with an adjustable folder was have a local gunsmith cut an angled peice of steel bar stock to fit, and silver solder a Marbles adjustable folder to it.
Now I have been told a company, New England something or other sight makers, are making a peep rear for the 527M, the ONLY outfit that does - nobody else makes a rear sight for the 527M. Good hunting!
Edit, this is the outfit, but they no longer list a peep for the 527M. here is what they DO have, http://newenglandcustomgun.com/
click on peep sights, and they have one that attaches to Weaver base. Will that work on the CZ scope mount? No idea - call -1800-955-4482 and press for gunsmith. Mike would know.