1. Is it a muzzle-loader, or does it break open like a double-barrel shotgun?

2. Establish a (free) account with Photobucket.com, upload your pictures to your Photobucket account, and then post each picture's IMG Code (found by passing your mouse over the photo). Click on: https://login.photobucket.com/

3. Be sure to post photos of the markings!

would be a muzzel loader--does not break. will try the photo idea you suggested and see if I can make it work. thanks for responding.

O k, I think I got the photos uploaded to the photobucket. There are 8 photo's in a public album under the name of MIKE3418. The only IMG code I saw was the same for all photos.
It was Image hosting, free photo sharing & video sharing at Photobucket. I pulled each one up after loading and all had the same number on them. figured it was because it was an album type post. Let me know if it worked---like my Mom always said "even a blind hog finds an acorn every now and then".
Mike P

IMg number ---again ---was 11096. if that does not work try 11098. posted several.

Mike;
Go to your own Photobucket page, where you see your own images of the gun.
Move your mouse to make its onscreen pointer rest on one of your images. Automatically (after a second) a box will drop down below the image to show the various available codes. Move the onscreen pointer down the box to the IMG Code, at the bottom, and click on it. Its box should now momentarily read "Copied." Paste the copied information to your forum post (maybe using the forum's "edit" function), and then repeat the process with the other picture(s).
Now your pictures will show within your post, just like this one of my granddaughter and me:

It looks like I got the pictures loaded. check out my post just before your picture. By the way---cute kid. I also found out yesterday how to hold and NOT to hold my new Ruger LCP380
It was the first time I have fired a semi auto and was not use to the slide. My left thumb found out rather quickly--have changed by grop from double hand to "cupped hand". Not to worry--the laceration will heal. ; ( You know what they say---"you can't fix stupid" all I have to do now is set the new Crimson Trace laser site. Thanks again for your interest in my old pistol.
Mike

found a very similar pistol at auction here

Crescent City Antique Gallery

they date their pistol from about 1840.... since the percussion cap dates from about 1830 and the gun doesnt appear to be a retrofit i think yours is pretty close to that date. your gun looks to be the same style and may be from the same maker.

i checked my list of all the major european proof houses for the marks on the trigger guard and can not find anything matching. my guess is that the marks are the gun makers mark.

I believe that, as usual, Ted is correct: It's a Belgian pistol that would be described as "bag-butt, screw barrels." However, there's an outside chance that it may be English, too.
Note that the Crescent City Gallery does not list a maker for the pistol they're selling. There were so many small gunmakers in Belgium that the initials on the trigger-guard of your pistol, though clear, would probably prove difficult to trace.
(An English gun of this period would have distinct, visible proof marks, while a Belgian one made for export might not be so marked.)

The shape of the hand-grip, like a cloth bag or even a bull's scrotum, makes the term "bag-butt" appropriate.
The four notches you see in the muzzle of each barrel fit a wrench which came with the gun (now probably lost). With the wrench, you could unscrew the (certainly rifled) barrels individually. Removing a barrel would present you with a hollow, tube-like chamber into which you would pour a measure of black powder, which would then be topped by a round ball. The chamber will be found to be of slightly larger inside diameter than the bore of the barrel, to make loading easier.
The length of the inner chamber would automatically limit the amount of powder you could put into it, and its interior diameter would limit the diameter of the (soft lead) ball. Thus, a safe charge was guaranteed.
IIRC, sometimes the barrel wrench would include a built-in bullet mold.

If you intend to explore the barrels' interiors, I suggest removing the wood and then soaking the entire piece in penetrating oil, while you fabricate an appropriate wrench to very closely fit the barrel notches.
This soaking would also make further disassembly easier, allowing exploration of the lockwork, which should consist of separate mainsprings, sears, and triggers, the sear notches being an integral part of each separate hammer.

I am willing to bet that, because of its condition, this pistol, though historic, will be found to have little sales value.
The best thing to do is to clean it carefully, but without any attempt at removing its corrosion-caused "defects," which actually add to its value.
You might try to trace the ownership of the property on which it was found, in order to discover any historical associations with the pistol. Considering its date, it may have Civil War or Western Expansion associations.

Oh, yes: Don't try to shoot it!

Thanks to both you guys. That is a great bit of information. I will try to clean it up like you suggested , with the oil and try to make a wrench.
Finding the property where it was found would be all but impossible since my dad passed away about 17 years ago.
When I get it cleaned up (or during the process ) I will take some more pictures and pass them along.
Thanks again for all the trouble ya'll went to and the information you supplied.
Mike P

That there pistol is so old, makes me want to "slap my momma"!!!