Congratulations! The 52 is a very fun gun, but comes with some amount of mechanical baggage. Make sure you don't dry fire the pin. Even if you never dry fire it, it may not matter and the firing pin could be toast regardless. Harrington products makes a replacement that is far less prone to breakage.
Oh, and NEVER trust the decocker to decock the gun safely. Some CZ52s will fire if there is a round in the chamber when decocked, and it's almost impossible to tell when a working mechanism will fail in these guns.
Stay safe, and have fun with the new gun! You got it for a very good price, IMO. I'll always miss my 52, that's for sure.
ETA: Harrington also makes hardened tool steel rollers to act as more durable replacements for the originals.