Also FYI,
Don't be tempted by this guy on GB below. Spend the money with Ken at Specialized Armament (even though he isn't the easiest to buy from, cheapest vendor, and not the fastest to ship)
https://www.gunbroker.com/All/search?IncludeSellers=1600002
https://www.gunbroker.com/item/759683105
I bought from him, they were obviously not Colt parts (as confirmed by multiple folks here in a thread last year). The seller then charged me a sizeable restocking fee to take his non-Colt parts back ($50ish) and was slow to refund my money.
I gave him an honest "D" rating on gunbroker and then he retaliated and gave me an "F" rating, because I had the gall to return his crappy mix-master non-Colt part (that were clearly not the ones in the picture of the auction) and eat a huge restocking fee to return them.