You could wash the fabric and that would take away any "sizing" on it that makes new fabric kind of stiff and shiny. That might make the fabric too soft, though, to act like a rectangle standing up. You might try just putting the fabric in the clothes dryer for a bit, along with something to kind of pummel the canvas and that will soften it a little. Tennis balls or a clean canvas shoe (close the shoe in a pillow case if you're not sure) in the dryer works for this kind of thing.
I like ziplock bags for smaller pieces...they can't fall out and you can easily see what inside. If you punch holes in the left side of the bags (opening at the top) you can put the bags of stuff into a notebook, which further protects the papers and makes it easy to store.
Add my compliments to your list...lovely fabric and great job! I was thinking that if you were making one as a gift and couldn't try on, you could make the halter part a tie-behind-your-neck, or make one end of the halter strip with a few buttonholes near a finished end so the length could be adjustable by buttoning it to one of the buttons. (That would be an option for those who can make really great buttonholes...not me.) But actually, I like yours best, just like it is.
Thanks for struggling with this! On my bag the tabs are "standing up" side-by-side with the chain against the back of them. And there are four strands of the crochet cotton in each loop through the tabs, not just one like you'd just sc around them. It looks like you make the purse by adding horizontal rows until it's tall enough. On mine it looks like the bottom is a single row crocheted in to join the front/back/sides. The sides are one pull-tab wide, and the crocheted joins have enough slack to just turn the tab 90 degrees to create a "side". This doesn't even make sense to me and I have the bag in my lap! Maybe I can figure out how to post some images...would that help?
Depending on what you make the card holder out of, you could just add a short fabric loop to run the neck strap through, or sew a metal D-ring to the top of the holder. And a thought for your mom with those folks around her...more and more those around-the-neck straps are made with a breakaway connector in them. (Cat collars have had them for years.) That way, if someone grabs onto the neck strap or it accidentally gets caught on something it will disconnect rather than hurt you. Good for you for thinking of your mom.
If the papers/fabric samples/bright ideas, etc won't all fit into a clear page protector...you could try using large ziplock bags (gallon size). If you punch holes in the left hand side of the bags to fit in a 3-ring notebook you have nice, roomy, see-through and securely-closing places to keep projects organized. A couple big D-ring notebooks and a box of ziplock bags can help organize a lot of stuff.
I searched everywhere, too, and finally just broke down and bought the least expensive Escama clutch. I just received it and I'm still stumped. I'm going to have to take it to someone who is really crochet-savvy so they can figure it out for me. If I have any luck I'll let you know...this has been bugging me for ages, too!