ATC SCM40 in house tweeter & midrange

How can one tell if an ATC speaker (SCM40) has the better in house tweeter and midrange?  Is there a visual way to tell, SN decode, etc?
Email the serial number to ATC and ask...
The faceplate/waveguide and number of screws. 3 on the new ATC tweeter. 4 on the old Seas one. All versions use the ATC mid.
Perfect, thank you!  This is one of the values of this forum.