E body cruise control wiring

I'm working with Tom at M & H to get reproduction cruise control wiring available for E bodies. He has the engineering diagram for the engine side of the harness, but couldn't find anything on the passenger compartment side of the harness.

I happen to have a complete original setup here which he can use to fill in his missing information if I send it to him. However, he would like to keep my original harness as reference material and give me a discount off my purchase price for it. What is a fair value for both halves of an original E body cruise harness in good shape? Just the electrical wiring harness/firewall grommet etc, NOT the servo, brake switch or turn signal lever.

Since I may never see this harness again, does anybody have any questions about it before I ship it off?

I'm installing this into a car that was not originaly equipped with cruise control. The cruise wiring grommet uses the same hole as the 4 speed reverse light. I need to drill this hole in my firewall. I know where to drill, but not what size to make the hole. Will someone check the hole size on their car for me so that I can get this right? I'm thinking it's about 5/8ths diameter?

Thank You

Tav

In case some of you haven't seen one, this is what it looks like... I was told this is off a 70 challenger. Does it look right to you guys? I wouldn't want to send him the wrong thing.

Tav

Another thought just crossed my mind. If any of you have harness part # or the missing engineering drawing available that shows wire lengths & connecter part #s, grommet size etc. could you send that to me so that I can pass it on to Tom?

Tav