Really fiddly, but worth it. After deliberating over how to fasten the book covers, I finally settled on Norwegian metal clasps of the sort usually seen on expensive hand knitted jackets. Fortunately I found some in a local shop at the weekend. The bible cover needed three, and I decided that these fleur de lys style clasps in an antique brass colour looked perfect.
It was hard work getting the needle through the binding, and particularly tricky working the hook half of the clasp as I was having to get the needle inside the enclosed flap for the front cover.
The little prayer book case has two much smaller clasps in a pewter colour.
I had the same problem sewing through the binding, and took the precaution of putting a small piece of iron-on interfacing on the inside to thicken up the fabric for the other half of the clasp. The prayer book is a very snug fit in this case, and I was worried that the clasps might strain on the stitching, but as it turned out they work really well.