Hello, I am brand new to the forum and this is my first post. I have been a vintage watch collector for years and just purchased my first Omega. I was not looking for this watch but it was offered to me and I could not refuse. I am looking to verify its original as I don't know much about Omegas. I know the crown, chrono hand, mainspring and crystal were replaced as the watch came with the original parts. The watch is running slow so I need to have it serviced. Any idea what a fair price for a service on these would be? Any input is appreciated. Thanks!