Will any correct sized watch strap fit my Omega Seamaster Racing 300m?

Hi
I have a Seamaster 300m Chronometer Ref 28695291. http://www.omegawatches.com/collection/seamaster/racing-chronometer/28695291

However, the rubber strap (98000087) is broken and I want to replace it with a non-oem band - thick/padded leather with stitching or similar. My research tells me my band is a weird 21mm width band (I can't find many normal bands with this width!)

My questions are:
- will any 21mm band fit? - its impossible to find any bands that refer to my watch!
- Ideally I want a curved end band so it fits snug like the original like here: http://www.watchstyle.com/pi-1473819992.htm . Can anyone recommend somewhere to get a band that will fit my watch? Hirsch appears recommended by the forum, but how do I know if it will fit my watch (will the curve end be snug), and secondly I couldn't find any curved ends with a 21mm width!

Any ideas much appreciated!

thanks

Also, keep the original buckle. One day, in the future, some collector will thank you for doing that.

ok i'll try for a 22m Hirsch...will come back with before and after shots...