Yes, they bolt up just fine.
I have the JDM RHD power folding mirrors & my US manual folding mirrors, I interchanged the shells so that I wouldn't have to paint them too. The mounts are definetly specific to LHD or RHD applications.
The only parts that are different are the mounts (triangular-bolts to door), the mirror glass, the black plastic bottom cover plate, and the frame that holds the mirror motor/ power folding motor & wiring plug. The black triangular rubber/plastic gasket that goes between the door and mount are the same. It's even stamped with the same part number. It is the horizontal tab that is molded into the triangular piece that bolts to the door. The mirror rotates inward on the mount. (see 2nd pic in Post #2, and only pic in post #4 - white is US, Green is JDM)
When looking at it from the top, it is angled to far aft. The mirror can't be adjusted, unfortunately. If shims or an angled insert plate was used between the mount & door, the threaded female ends would not line up with the mounting holes correctly. Unfortunately as well, the US bases don't have the mounting holes/threads to accomodate the JDM mirror frame (see pics above).
A LHD power folding mount mount would solve my problem.