Welcome. I have found this place to have quite a lot of used parts for 65-70 Impala's. https://www.facebook.com/groups/319429308116921/
Just post what your looking for, and someone will answer. Also try our classifieds here in the parts wanted section.
I was told that the moldings from a 70 impala won't fit the 69. I wonder if this is true or not.
In the US back in the sixties the American car manufactures used to change the car's appearance annually by using different trim and grills every year to allow consumers to identify this years car from last years car model. Consumers used to buy a new car every three years or so because they didn't want to be seen in a car that was too old for emotional reasons. There wasn't anything wrong with their old car that was designed by the production process to offer trouble free service for five years and to then start to fall apart after seven years so that there wouldn't be any old models still on the road.
This was all expressed in the phrase "keeping up with the Jones'" as there was noticeable social pressure to buy and consume products to express how wealthy they were to their neighbors. It was all for show, and many Americans were conditioned by advertising to have the "right" clothes, the newest TV or electrical appliance. The clothing designers sewed on a lizard or polo player on their clothing to allow others to check up on your purchasing the correct shirts or not. You had to show your badge of compliance to show that you were a follower of whatever the advertisers wanted you to buy.
Personally I never subscribed to this phenomenon when I was young as I was dressed in either a uniform (US brown shoe Navy, or as a police officer) or in my alternate uniform of blue jeans and T-shirts. I drove older used cars, so the money I that didn't spend on a new car I spent on building ever increasing levels of engine power (and whatever was left over was spent on fixing parts that broke such as rear ends as a result of increased power). The only way I got a different car was someone buying my current vehicle out from under me because they wanted it more than I did; as proven by the amount I was paid for the vehicle. With these funds I started a new project to build a bigger motor in a lighter car to become even quicker than my old ride. Which started the process over again.
I have visited this forum over and over in the past without registering, but I am always impressed with the support and dedication members offer each other. Please keep up the great atmosphere. I will definetely check out the facebook group.