I don't believe that MCD called it EVO until the EVO2, but that doesn't matter.
If you are looking for parts and are in the states, go to
http://innovativehobby.com/ they are great. If you have any questions, you can shoot them an e-mail and they will respond rather quickly.
The CC of the engine should be stamped on the head just below the cooling fins. You might have to take off the plastic shroud. Also, they will not write 30.5cc they will most likely say 29cc. It's still a 30.5cc but I don't know why they don't stamp it like that.
You will have either a CY or a Zenoah engine. O'neil does is make it perform better, such as porting etc... I have never owned one of their motors so I don't know if they engrave them or not, some companies do that. Check under the plastic shroud and there might be some markings there.
Hope this helps
Chris