50's Mint Sets

1954 Mint P-D-S
$550
1955 Mint P-D-S
$313
1956 Mint P-D
$300
1957 Mint P-D
$481
1958 Mint P-D
$313

Above are Numismedia values for original US Mint Sets in original packaging and not cleaned or tampered with.

If you get the hand assembled sets in Capital Plastic type holders the values are probably less than 15-20% of that even in mint state uncirculated.
Cleaned, even less.

Where do I remember reading that early mint sets actually had two of each coin?
This would be important, seems I read that someplace. These are quite scarce.

No you can't tell if they were originally from the US mint package or hand assembled. This is a case of the original mint packaging adding to the collector value of the set.
On the other hand, if you could find an empty US mint set holder with no coins in it, it would have substantial value by itself and adding the correct uncirculated coins to it could be done and nobody might be able to tell the difference.
The fact that was pointed out that these original coins have attractive toning when they are found in original US mint set packages of that era, might be hard to duplicate. So they are best just the way they are.
Look on ebay for a 1954-1958 US mint set that is original. You'll see a big difference in prices and there's good reason for that. Your cardboard holders are worth money too.
Look at the value of this one 332248957748 and notice yes, they are complete when there are two coins from each mint in the set, now that I look at it. Each folder has two of the same coins that were minted that year from each mint that made coins. This ended at some point later but early US mint sets were like that.
Compare the value to several hand made sets in plastic.

I had 1947, 48 and 49 mint sets in the OGP about 20 years ago. I miss them terribly!

I told the guy that I sold them to to name his price when he gets ready to sell them! As usual, he ain't ready to sell!