Re LO and export JSFs:
The UK will get US-standard aircraft because they're designed to the same Joint Op Req Document (JORD). This defines signatures as a Key Performance Parameter (KPP).
All other export aircraft are designed to individual ORDs negotiated bilaterally and forming an appendix to the big PSFD MoU. Clearly, these may contain KPPs that are not the same as those in the US-UK JORD. Indeed, there's not a lot of point having them if they don't. Notably, these bilateral ORDs are described as being compatible with "national disclosure policy." Which means that it's more than the Norwegians wanting a brake parachute.
So while the good Col. Richard Harris (does he occasionally break into "MacArthur Park" in classified meetings? We do not know. But I think we should be told.) tells the Norwegians that there will be no differences in signatures, that issue is still technically subject to negotiations.