Hello ! All in the title...
I own a Graham Chronofighter Oversize Diver Deep Orange, Watch, I love !!
Unfortunately I tore the strap
I bought a strap on ebay but it's poor quality, hard plastic, and does not fit well the watch...
Are you looking for a replacement rubber strap with Graham marking or you want a custom made leather strap? There are some strapmakers able to make some fantastic leather straps that follow the curvature between the lugs, just as the rubber strap.