Hello all,
For an undercover campaign, the pilot is allowed a choice between 3 different fighters, e.g a Myrmidon, Herc II and a Perseus but will have to keep that specified fighter for the rest of the campaign.
The trouble is a "disallowing" SEXP is non-existant I believe, so although in-mission I can successfully identify what class of fighter the player is flying I can't make the only choice of fighter the fighter the player uses in the first mission.
I tried a hack:

Here I have identified what fighter the player has chosen and recorded it in a variable.

In the campaign editor, I have not allowed any type of ship to be always available initially at the start of the campaign but made the Myrm, Herc II and Perseus available in the first mission's Team Loadout. So depending on the choice, the allow-ship SEXP will always allow the specified fighter to be always available until the end of the campaign and no other.
Alpha 1 in the second mission of the campaign is flies a default Ulysses in-FRED depending on the ship-allowance changes to remove it.
Unfortunately, this seems to cause problems which include only the Myrm available in the ship selection, no weapons and no effect in the next mission. Any ideas?