It is a very well known shop in Paris, but another one is cheaper with same quality : Camille Fourner http://www.camillefournet.com/en/create-your-watch-strap
Their quality is very high. However they do not offer the material and or options the ABP does. However, you pay dearly for ABP. What the hell: It's only paper
I've had a couple Camille Fourner straps, most memorable on my Blancpain Villeret. Man, are they comfy!
Just looked back at my CF order last year. Ordered Saturday Oct 11. Shipped on the 17th. Arrived in the States on the 20th.