I just googled it. They look absolutely BEAUTIFUL!
I would say it's a labour of love, if you like handy crafts, sewing, embroidery, appliqué and so on then you should make one, enjoy making it and enjoy LO 'reading' and playing with it.
If you aren't really into needle crafts then just buy one of the many great fabric books that are on sale (or for that matter the textured activity toys), they have lots of different textures to touch and feel and in my experience LOs love them and will play with them for ages.
I'm sure if you made one of these quiet books your boy would love it to bits, and what a lovely keepsake too, could be passed on to his children!