Okay please forgive the bump of an old thread which is probably long since dead. But with the release of the "Saving Mr. Banks" there may be some popularity or interest that might surface and here is some information I have discovered in the process of researching making my own carpet bag.
Here is a great photo of the D23 listing. Its high resolution and you can see the great detail in the the shape of the leather strappings and the nail heads that tack them to the inner frame.
You can also see the material "pilling" because this is an actual carpet bag.
Note: Carpet bags were generally made of carpet remnants because of their ease to carry and to stow in tight compartments. They would protect the contents from the friction of traveling and cushion them from the constant bouncing in storage.
So if you are looking for some authentic materials I would start looking at rugs and carpets of the time. Here is a link to an over stock item that is close to the design but it is a modern version of the style.
Hand-Tufted Mandara Transitional Floral Black Wool Rug (5' x 7'6") | Overstock.com Shopping - The Best Deals on 5x8 - 6x9 Rugs
Note: working on sets and specifically with props this bag was probably made on the set from remnants of carpets that were on the sounds stages for old productions. The reason for this is it is difficult to find several similar bags so squaring off identical pieces from a carpet that was laying around would be easier than hunting down several bags. (which is still possible)
I am going to take a stab at creating a template and tutorial for this bag because my wife would love to have one for Christmas. When I get it finished I'll post it up here!
I hope this helps everyone.