Yes and no...
By: Mike-On-A-Bike : April 22nd, 2020-23:24
Since both have lug width 20mm, technically it should fit in the space, but may not “fit” the case as the GMT has the beefier maxi case in 40mm and the Datejust is a slimmer 36mm. You may end up with some parts sticking out instead of sitting flush.