Just tossing this in. If you decide to line the interior with wool felt, find the closest billiard table retailer and you'll find he has it in his shop. It's actually a bit heavier and denser than the shooting case material, but, easier to find. I don't think it's any more difficult to work with. Latches, hinges, corners, etc., try Rockler Companies in MN.

Good luck with your project. Post photos from time to time.

I will second what John says, but Billiard Table cloth is a worsted wool, and unlike felt, it is a woven material, and is easily worked, and easy to clean with a dry brush. Felt is a random, pressed cloth and frays easily.
I get my billiard table cloth from a woman on ebay and I use 3M 7700 spray adhesive.
Peter Dyson, in England sells precut dividers, but I make my own. He also sells all sorts of gun case hardware.

John and Edgar,
Thanks for the tips. Building a case, while fun, is challenging. Methods like which adhesive to use for case liner material are indespensible. Are there any other tips regarding building methods any of you builders might have?
I am interested in making this thread the go to for those needing information on case building. I know that there are many more cases out there that are just dying to be shown. Send in more pics and stories about your cases with and without guns (try to include dimensions and scale when possible). Don't hesitate to link other forum entries to this thread as well. There is probably enough valuable information hidden in the pages of this forum to make many volumes (and a set i'd happily pay for). If you know of old threads that will lend useful information, then by all means, add them.
Keep the information coming. Your experiences are welcome and necessary for a successful build, and thanks to everyone who has contributed so far.

Case to O1248
 

Here are pics of case to gun number O1248

David,
Absolutely gorgeous! The close ups are really great at helping understand the methods used to add the top and bottom to the sides. Any dimensions you care to give would be appreciated.

I took some quick measurements.

External: 33 3/8" X 9" X 1 3/4" Total height closed is 3 1/2" so both top and bottom are identical.

Internal: 32 1/4" X 8" x 1 1/4" case body is all made from 1/2" wood.

The divider is 32 1/4" x 5 3/4"

I doubt this to be the original case to this gun. It needs to be about 3/8" wider and the small barrel block is cut for a dolls head extension which this gun doesn't have.
I need to make a spacer to hold the barrels in position so they won't hit the stock when the case is tilted.
I hope this helps.:)

David,
The case looks like others i've seen. You're probably right about the gun not being original to the case, but it looks like other parker cases indeed. Another note is that the cases I've seen all have the stock and action bordering the edge of the case. The void created by the other side of the wooden insert that holds the shells is just enough to fit the barrels on the opposing edge of the case. Is it possible that your insert has been lifted out and moved so that stock/action and barrels are all jammed together. Perhpas this was done to accomodate a larger gun, other than the original one that the case was made for? Just wondering.
For some photo's of what i'm describing, check out the pictures that Bruce (BD) posted. The link is on the fifth entry, on the first page of this thread.

Best
Dean

Dean, you are exactly right about the insert. I have tried to position it so the barrels would be away from the stock and it just wouldn't fit.