Did the assembly line distributor caps on a 69 Hemi have aluminum, copper, or brass terminals?

Looks like aluminum to me.

Is that an assembly line installed cap or an NOS cap?

It's a very nice original.

What year and model car did it come from?

AFAIK all 68-71 cast iron duel point caps are the same.

Apparently some people think otherwise. The question of interest is what came from the factory assembly line? The way to figure that out is to identify known survivors. If its an over the counter replacement, its not a bad thing, its also useful info. If you don't know what the cap came from, then OK, just say so.

A member here asks a question about duel point dist.caps.As I tried to answer the question I typed As far as I know.Am I an authority on these caps no.I will say this,every cast iron duel point dist.I have seen from 68-71(340-440-Hemi)has had a tan Made in USA cap on it.If you think otherwise post some pics and information.I have three cars with that cap,70 Cuda 440+6 4 speed ,69 Coronet R/T 4 speed and 71 340 Cuda 4 speed.If I am wrong than let me know.

Here's one of those discussions.
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1198028/re-distributor-cap.html
Something off a survivor car is always good for adding evidence to what was done. Joesixpack there says he has various versions of the earlier black cap, all with the same p/n. Maybe there was only one versions of the tan cap, but that's where I was coming from.

I buy and sell all kinds and brands of NOS ignition parts. I have sold both black and tan IBK-1003 marked Prestolite distributor caps for Mopar dual point distributors. My opinion, if the cap doesn't have the IBK-1003 cast on the inside of the cap in the vicinity of the carbon button, it isn't a factory correct distributor cap.