Re: Masters License
Does your contract state how they define "master electrician"? Usually that means someone with a government-issued license, credential, certificate, etc. rather than someone who is certified by a private organization like IAEI. So in all likelihood, you would need to get a license from some state or local government entity.
Unfortunately, the procedures for doing this vary greatly from place to place (some states have statewide licensing, some don't, and some localities have their own licensing rules). Your experience would probably qualify you to take the necessary exam. I suggest you find out what qualifies as a master electrician in terms of your contract, then pick a US jurisdiction where their license will qualify you under the contract.