Ken
They are both correct...
I guess the real issue is; do you integrate the listings into one or keep them separate? or link them in some other way!
Aircraft when built and supplied to the Swiss, were mfg'd as F-5E Tiger II's.
When returned to the US military and supplied to US Navy aggressor squadrons,
they were upgraded modified to F-5N standards.
Some examples:
76-1531 (c/n L.1006) J-3006 to US Navy marked as 761531
76-1532 (c/n L.1007) J-3007 to US Navy as 761532
76-1534 (c/n L.1009) J-3009 to US Navy as 761534
76-1535 (c/n L.1010) J-3010 to US Navy as 761535
John