Your 527 is set up to take 16mm dove-tail rings.
If you intend to use a one-piece mount, you will need to drill & tap the receiver.
I have a 527 and use Warne Maxima Permanent steel vertical split rings, it's a very solid set-up.
Should you decide to go ahead with a one-piece mount, I've used a couple of Ken Farrell mounts, on Savage varmint/tactical rigs, that I liked very well.
Link to Ken Farrell -
CZ527 Varmint w/ Bushnell Elite 4200 6-24x40 & Warne Maxima rings.