lua_target_monitor.txt:

1.
interceptor = {
ship_s = "M2",

must be M4

2.
smalldrone = {
ship_s = "M5",
},
lasertower = {
ship_s = "M5",
},

to

smalldrone = {
ship_s = "DR",
},
lasertower = {
ship_s = "OL",
},

That's what both were from ship tag. These tags were Y+Class+2 letters - 2 numbers.

DR is self explaining drone.
OL i would interpret as orbital laser.