If the spanker does billow the wrong way, I'm not sure how to fix it - billowing does not seem to be controlled by locators.
Anyway, I've modified the GoF model to use the same locators for the mainsail as "FR_Sloop". While I was at it, I removed some locators from the hull model which are to do with lighting in AoP and later games, which PoTC doesn't recognise, and which means I can remove the "fonar" files. So:
The spanker at least moves correctly as per GoF
and the mainsail doesn't foul the jibs as per PoTC. Best of both worlds.
"FR_Sloop", being the model I used for the first version of what is now "Sloop4", naturally also has the same spanker problem. So I made a revised "FR_Sloop" by copying and renaming "FR_Sloop4" and hex-editing the hull model to use the "FR_Sloop" texture.
Le Rève will now also have a spanker which moves correctly.
You may be wondering what happened to "Sloop3". Judging by the names of the texture files ("bortoutsloop1.tga.tx", "bortoutsloop2.tga.tx", "bortoutsloop3.tga.tx") "Sloop3" is actually "FR_Sloop".