Perhaps you should contact Ken Cross & talk to him directly. He is a licensed professional and can help you sort things out. He has offered help and will likely give you better advice & guidance as compared to the rest of us! By the time your rigger gets to the boat in two weeks, you will know what you have on hand and additional items to purchase ( if necessary).
Electrical & electonic components can be very difficult to troubleshoot & repair, especially if you don’t have experience. Thing about a vhf is that it is a very important piece of safety gear. If you ever have an emergency, you want it working at maximum efficiency. If it’s working properly, you should be capable of transmitting approximately 20 miles on a clear day. Be sure to keep us posted on your progress; would really like to know the outcome!