RAF Brevet identification

[Fred Davis]

Hi, sorry about this, I've posted this twice, but just realised it wasn't in the correct section (i.e RAF), so I've copied & pasted it again!
I'm afraid this is rather long-winded, & I thank you for reading.
I've recently become interested in the RAF, & was looking to find info on some RAF brevets I've been given if possible.
I've trawled the internet, but can't quite find the info I'm after.
They're reproduction half wing brevets with brown wreath surrounding a letter (eg 'B' for Bomb Aimer). I really need to find out which are from the WWII period or not.
I have the following letters on the brevets: RO (Radio operator), D (Driver), MG (Mid Gunner), NG (Nose Gunner), FS (Flight Steward!!-can't be wartime i guess), QM (Quarter Master), FC (Flight Controller), Parachute Jump instructor, O (observer), RAF (Weapons Systems Operator??), W (Weapons Operator), AT (Air Technician), B (Bomb Aimer), N (Navigator), LM (Load Master).
I think the Bomb Aimer, Navigator, Radio Operator, & Para instructor are correct as I've found info on these. All the rest though, I'm not at all sure they are WWII period. I think the Load Master brevet may have been introduced in the early 1950s...not sure though.
Also, I have a feeling the Observer brevet is wrong, & shouldn't have the brown wreath, rather should be just a wing joined to an 'O'.
Thanks in advance for reading all that...I hope someone can help with this...And thanks for what lookis like a great forum.