Coming up with the right MDH or even the right date is going to be harder than you think. Accually you may never know what is correct if you don't have a picture of your origonal sticker. I say that because of what I found on my 73 Challenger.

927 SPD
10-72 on door sticker
121216 MDH (there is a typo...the first 12 should be a 10)

The SPD on the fender tag doesn't always match the door sticker and the MDH is going to be impossible to accuratly guess.

If no one comes through with the weights for you, I can see what my 73 Challenger says.