The below news update was posted on the RAF Website not too long ago about a few WSOps who have been training with FAA Observers. Again it's a bit vague but it states that it was a 16 week training programme.
RAF train with the Royal Navy at RNAS Culdrose
I'd take a guess that the WSOps are due to go EW as 750Sqn fly a beefed up King Air (Avenger) with Sensors etc in the rear?