Chevrolet Impala '70 details
 

Hi! I am an audio installer from Latvia, and I have an oldie '70 Impala that needs soundsystem in it.

But the thing is, the owner did not renew it in any way, so many parts are old, and, as I will be having a need to remove some panels to wire them, some sealing details (and maybe the panels themselves) need to be changed for newer ones, as they are already turned from fine rubber to stubborn wood. We don't have details like this lying around, and also I don't know any webshops that sell ALL the parts of the car in a radius of 1000 miles.
So, could you suggest/tell/link a site/dealer that would have a catalogue of details for Chevie Impala 1970 in the States or Canada.

Thanks!