Marshall Islands

I think that if you look hard enough, many of those Marshall Islands $50 silver coins can be had at near melt.
I read a classified ad in this week's Numismatic News where someone is offering Marshall Islands coin dies and hubs for sale, undefaced.

The hub is a reverse of the die. They take a die and hammer it into a hub, then they can work in relief to carve the design. Then they hammer the hub into a new die. Eventually they come up with a working die from this sort of back and forth process of positive and negative.
A die/hub that is undefaced hasn't been cancelled -- essentially destroyed -- by carving an X across it and such.
I can provide you the person's email if you want.

ebay has a couple of auctions at this time for Marshall Island coin hubs, starting at $189 plus about $10 postage and handling.
BTW: I just checked my records and had paid $14.39 for a $50 silver Marshall Islands Columbia Space Shuttle coin.

AH yes... high-face-value Marshall Islands coins. I've heard stories about these.

Story goes that the Marshall Islands government began to regret issuing so many coins with such high face value when tourists began to turn up in the islands with box-fulls of the things. They'd march down to the bank and demand face value for them - in US$ (the legal currency of the islands). The Marshall Islands government was losing money, badly - these "tourists" were earning up to $40 or so per coin - enough money to pay for the trip, with a tidy profit to boot.

If the black market (or at least the grey market) is selling undefaced hubs and dies, that only makes the situation worse - anyone with a coin press could obtain dies and churn out as much genuine-looking money as they wanted.

In the end, the MI government had to slap restrictions on the number of coins that could be imported or redeemed at any one time - effectively making their own legal tender coins no longer legal tender. There's a little note to this effect at the end of the introduction to MI coinage in the Krause catalogues.

Recently, when the Cook Islands got wind that these shady types were going to target them next, they promptly revoked the legal tender status of many of their high-face-value coins.

Hope this doesn't put too much of a dampener on collecting the series for you. Just be aware that they may not have very good investment/re-sale value... unless most of them end up being smuggled back to the islands, redeemed, and melted down!

Now, for your coins in particular - you're sure they're silver $50 coins? The Monitor and Fanning/Nicholson designs are listed for the cupronickel $5, but I can't see a "Louisville" at all. Like you, I've only got the 33rd ed.

Your coins might even have been designated "unofficial", and listed in the Unusual World Coins book.