In Japan I picked up a Speedy Pro 3570.50 and trying to replaced it with a leather strap. The Omega dealer said it will take 3 weeks to get the strap that I want, so I went to other dealer and found this great strap made by Bambi, I like thick leather strap and found this to be the thickest compared to my hirsch strap on my speedy reduce.
It is made with the famous Matsusaka Cow (Matsusaka beef - Wikipedia, the free encyclopedia) , very interesting to find out what it is :p , I like how the clasp is flat and rounded (it's hugging the strap when you are wearing the watch). Stitches were done by hand, and looks very strong and tight. The leather looks glossy on bright lights and outdoor, very noticable. Two drawback are it's a but heavier than other leather band, i like lightweight leather, and worse of all, it cost 18000 yen (around $230+) - but considering the type of material and cow they use, it is bound to be expensive.
The Bambi deployment clasp DID NOT work with it because it's too thick.
ƒoƒ“ƒr | Bambi Official Site