Hello,
not sure if this is of interest to some of you who still uses the old sony readers with the plastic spine. But I like to describe my procedure.
My covers were literally falling apart, so I tried to make new ones. With the PRS 505 I used the original spine which I removed from the original cover. For my 650 the spine broke, so I printed the two parts with my 3d printer. I used:
-Cardboard 2mm (too thick) and 1mm (better)
-Sticky faux leather (or whatever you prefer)
-original 2 part spine or printed ones (left is the "lower" and right the "upper" part)
-cutter, scalpel, cutting mat
-my good old sewing machine from my grandmother
1. Cut the cardboard matching the old cover
2. Place the two cardboard parts on the sticky faux leather with a space in between (for the spine and the folds)
3. Place the lower part of the spine in the middle between the cardboards
4. Cover everything with a second sheet of sticky faux leather, you see the bulge of the spine in the middle better in one of the next pictures
5. Cut the overhangs
6. Now you have to cut holes in the sticky f. l. to free the holes in the lower spine. In the picture below I used a second spine to localize the holes
7. Holes
8. Attach the upper part of the spine to see if everything fits and the holes are big enough
9. Remove the upper part of the spine to sew the margins. I did that to prevent the fraying of the edges and because it looks good (in theory...)
10. Okay, some problems: my cardboard is a little bit small because I forgot the width of the spine itself, when I measured it, and the seam is not very good because the thread tension was too low, although I had tried the seam on the leftovers, but here it is:
I printed the spine with nylon. Time will tell if everything is stable enough.