Instead of doing the wise thing and using Kent from Oz's method for stretching a pen loop, I just forced the pen in and out, thinking the loop would stretch with wear. Instead, it was the threads attaching the loop to the cover that gave way:
I thought it would be a pretty simple job to have a cobbler reattach the loop and make it bigger. I brought my Filo, and an example of the type of pen I use, to my local show repair shop. I thought they could add some elastic to the loop so it could hold thicker pens, but after some testing they found that the rubber grip on the pen would snag on the elastic. They said they could attach extra leather to the loop and dye it to match, but since they would be stitching it by hand, they couldn't match the original machine stitching. They were also concerned that the job would be expensive, but I assured them more than once that I was willing to pay for quality handwork.
They did the job in just about a week, and it came in $5 under the estimated cost at $25.
|The original part of the loop is at left, the added leather at right|
|The pen fits comfortably|
|Without the proper equipment, my local cobbler couldn't roll the edge of the leather and stitch through multiple layers, so the raw edge of the leather is dyed to match|