Isn't this a great coin, RLH? These old dalers (pronounced almost like 'dollar') circulated in the Scandinavian countries during the 1800s. The coin in the picture is in beautiful shape from a numismatic (coin collectors) standpoint, since it has strong eye appeal and no problems like scratches, stains, nicks, or gouges. Nor has it been cleaned.
DO NOT CLEAN YOUR COIN. CLEANING RUINS VALUE.
If your coin looks like the one in the picture, a little better than average circulated, figure a catalog value in the area of of $400 US dollars. These are rare coins and you don't see many of them in good condition. Be sure you understand what 'catalog value' means. Use our Important Terminology link for a description. 'Catalog value' is somewhat of a weasel word.
worn: $75 US dollars approximate catalog value
average circulated: $400
well preserved: $600
fully uncirculated: $1000
All of the dates and mint marks are roughly equivalent in value.
The coin in the picture comes from The Coin Community Family, an excellent collecting web site with lots of knowledgable people and interesting content. The picture is on a Forum Thread where you can find thorough descriptions and gorgeous pictures of coins like yours.
In 1838, coins were made with two different assayer's initials: FF and WS. Some of the 1838 WS coins were erroneously minted with the initial backwards: 'SW'. These coins are so rare that the catalogs don't even report a value for them.
As always, you must also consider the possibility that your coin is a counterfeit. This is sad, but true. For a recent episode with a counterfeit coin on CoinQuest, click over to this link. Remember that any valuable coin might be a counterfeit. The sure way to guard against buying a counterfeit coin is to buy only from established, well-respected coin dealers.