Small breakthrough...Unquoting linkname values from ships eqp file will remove starshells effects...
Code:
;SH5 FX Update
[Equipment 23]
NodeName=M90
LinkName=NULL;5InchStarShellGun;NULL
StartDate=19380101
EndDate=19451231
;SH5 FX Update
[Equipment 24]
NodeName=M91
LinkName=NULL;scc_9_gun;NULL
StartDate=19380101
EndDate=19451231