The link you posted does indeed show a 1675 (BP) case, which would also be accurate for a 16750 as that case did not change from the 1675. However the BP 1675 case is not very accurate to gen. The BP side profile does not have the right curves and the CGs are crazy skinny. The BP acrylic crystal is correct for a 16750, however the rivet bracelet is not. The 16750 was only offered with oyster or jubilee. The BP dial coronet is wrong (affectionately known as "frogfoot" due to the outer spires being shorter) - this type of coronet never appeared on a gen GMT dial.
Your mention of this model being available with a 3186 is the first I've heard of it but if Ryan says so I would believe him. BP does make a 16710 case with a 3186 movement, you might want to verify that the case will stay the same. The 3186 has the hour hand on the bottom, which is correct for a 16750. As pictured in the link, that 16750 has the GMT hand on the bottom, which is not correct for model.
GMT Master History, Rolex GMT-Master, GMT-Master, Rolex
gmtmasterhistory.com
I did a blueberry in a 16710 case, if you want to see what that looks like.