It's early and my strap is in a box upstairs. Is this the Isofrane-ish 2 piece with many wide rectangular holes? If so, it fits a dream on my 8" wrist on the sword-hand SMP GMT model. Certainly have enough extra holes to fit around a jacket cuff so you'll be fine for daily wear.
Used to cost £100+£10 for the buckle, understand that has shot up but it does fit the case well and is wearing well since buying in 2012 and getting frequency use.
Can't comment on how it will be centred, sorry.