I'm glad she found it. I just saw this thread and have a brass stencil that is used for stitching as you described.

Not a sewing machine, but some misc blocks for a sewer / quilter. This is something each of you could do one block and send to one person to put together. I know I have seen an antique sewing machine block somewhere - maybe someone has seen it. I'm sorry she and your family has to endure this horrible disease. Making this quilt will help you all. Here is a link that might be useful: Quilter's Blocks

Your DH did a great job cutting them out. Love the way you have the pieces fit. The scissors she used are what you use to cut out patterns for stained glass. They actually cut it so that you do have a grout line. You did a great job of keeping the pieces in order and not forgetting like me what piece goes where...

I found this link about preserving the quality of the tissue paper pattern itself, but it doesn't answer your question about protecting the patterns from disintegration due to humidity, etc. (Preserve Paper Sewing Patterns) Reading a bit more here and there, I noted on chowhound that most foodsaver bags are not biodegradable until thousands of years have passed, and yet other info mentioned food saver bags break down over time and becomes air permeable. Maybe mylar bags would work better? Perhaps it's all about not only what you use, but the seal too. If I was doing this, I'd probably use lightweight interfacing on the pattern itself and hope it doesn't decompose (I have no knowledge or even guesses about this!), and/or I'd just opt to double bag the patterns in food saver bags and then put them in a tote that has a good seal on it. HTH!