I suspect what you hid away looks like this
This pistol was produced back in the 1980's in both finished and kit form.
Dixie Gunworks 1987 catalog shows an asking price of $83.00 for the kit and $108.00 for the finished gun.
The pistol is almost an exact copy of the Allen & Thurber Sidehammer Target Pistol as is shown on page 53 of Flaydermans Guide, 9th Ed.
The original guns were offered in .31, .41 and .45 caliber. but the Hoppe's gun was only available in .45 caliber.
The original's were made in the 1840-1850 time period.
Ethan Allen (the company went thru several name changes) was most famous for his pepperboxes but he made underhammer rifles and pistols as well as revolvers.
Hoppe's also sold an Ethan Allan double barrel pistol in .36 caliber thru Dixie.
If you want to shoot your pistol be prepared for some mis-fires.
The problem is due to the size of the hole that connects the bore with the flame channel from the nipple.
The flame channel is an extension of the forward threaded hole that holds on the sideplate.
While this threaded hole is large enough, the company drilled a very small connecting hole in the bottom of the bore. Too small for any of the powder charge to pass thru.
If you are fortunate (and don't mind doing a bit of drilling) you can find an "Aircraft Length" 1/8 inch diameter drill at Ace Hardware.
This drill bit is long enough to reach down thru the bore and drill out this small connecting hole to a usable size that will reliably fire the gun.
If you do this remember, you only want to drill thru the one wall. If you drill too deeply the drill will break out inside the frame. If that happens it will have to be welded shut from the inside of the frame.
You should also notice that this little connecting hole is not centered with the bore. It is below center at about the 6:15 o'clock position to align with the crossing screw hole.
Also, when you finish drilling out this little hole be sure to select a drill bit that slips easily into the threaded hole and run it in until it stops under the nipple. This will remove any burrs that were caused by drilling out the barrel's hole.
Speaking of nipples, this gun uses a special nipple. It is not available from anyone so be careful and don't loose or damage it.