Underdash wiring harness for 70 mach 1

Hi All,
Doesnt anybody make a underdash wiring harness for a 1970 mustang? This being my first ford restoration I would have thought that somebody would be making a replacement harness for this car? I dont want to use a painless harness because I am after a correct restoration.
Thanks Dave

Surely somebody somewhere knows about these or has delt with this situation before? Another thing I am finding out is that the major parts suppliers, Ground up, NPD,Larrys,Mustang barn,Tony Branda, all of these suppliers seem to go up to 1968 on a lot of their parts but not 69 and 70? Why is this? No demand for 69 and 70 Mustang Parts? Remember I come from a chevy background where just about anything is available for camaros and chevelles. I thought there were just as many mustangs as camaros and chevelles if not more, so when i chose this 1970 Mach 1 project I thought there would be parts available for this car? Maybe I havent found the right parts supplier yet? Any suggestions?

Thanks Dave