Hi everyone! I am new to the Mach 1 Club! so glad I found this group.
I am looking for a 73 Mach 1 that's all or mostly original and in the worst condition possible.
I am trying to find one for my husband, he is dying for a project car and said the Mach 1 has always been his dream car!!
Thanks in advance!!
-JBarr
Welcome!
Thanks for checking in, glad to have you here.
Your husband has good taste. 
We will be happy to help you in your attempt to locate the right project car. The 1971 to 1973 are basically the same car with only a minor few changes. Does your Mach 1 have to be a 1973?
I realize that you are looking for a project car but I would recommend that you look for one in the best possible condition. Otherwise you will have way more money invested just in body panels (not to mention the time devoted to rust removal and replacement) than the cost of a new Mustang. Purchase the best your money will allow.
So I guess the next hurdle would be to know what area you are looking in and how much are you hoping to get into the project for?
For example: I have a 1973 Mach 1 that is original except for the paint, the rims, the front seats and the transmission. Everything else is as it was born. It is an original Southern Arizona car, has absolutely no rust, has never been in a wreck, and only needs a headliner and carpet to make it an acceptable and complete weekend local car show contender. I would say that my Mach 1 as it sits would be worth $9,000. With new paint and the above mentioned work it would be a $17,000 car.
I purchased another Mach 1 about three years ago that needed everything. No motor, no transmission, gutted interior with rotted floors and cowl for $1,600 I sold it with a fastback with no useable body panels but a date correct motor and transmission for $2,900.
Those two examples should give you and idea of where you are with your search criteria.
Welcome to the site! I see Steve already has given you some great advice. I am sure there are plenty of 71 - 73 Mach 1's out there that have seen there day but I must ask why the "worst condition possible" ?
Welcome from Ohio
Steven gave some great info
One of the biggest things - with a project car is where are you located.
Transport can get expensive
Don
Welcome, worst condition possible is a tough place to start as there are some in very horrible condition. The rust on these cars can be extensive and is one of the major problems for a restoration. Steven was correct about buying the best your money will buy. But if that's the reason for the worst condition request? Good Luck we'll help all we can. JTS 71 Mach1
+1 on the 'buy the best you can' advise. Rust will kill both your enthusiasm and your wallet. Other than that welcome and enjoy.