On which tune? I haven't proof of it, but it could also be that 3 guitars weren't EXACTLY in tune with each other.... That's how Def Leppard did it on "Bringin' on a heartbreak"..... Never heard of Skyn using effects.
There is a lot of phase shifter use on Lynard Skynard stuff, The Breeze is a classic example. Probably the the ones built into Peavey amps, but they sound very similar to Small Stones.
Rossington is the one who used the phaser. They didn't start using the Peaveys until 75-76 (Bullets and One More era), so that's just a Phase 90 you're hearing on 'Pronounced', 'Second Helping', and 'Nuthin' Fancy'. Whether Rossington's personal Peavey had a built in phaser or not after that time, I'm not sure.
Thats a vibe pedal(as i'm sure you know)much more of the Jimi,trower thing.Thats gonna get much more wobble then that song has going on,but most drunk cats at a bar won't tell anyway Exactly why I use a phaser for vibe stuff.It's close & most don't need it to be dead-on.
But if your the guy that does the Mojo is the ****
I've always found the best way to get a vibe-ish phaser sound was the old MXR phase 45. I have an old DOD copy of that pedal for sale if you are interested. Great sound in a very good condition vintage box.....PM me regarding it.
tis actually a good pedal. Ive got it here sittin between my acoustic and 4 track playin some I am the Walrus and damn it makes it sound nice. Not too psychedelic, but enough. Have it sitting 1/3 of the rate up. Turned the rate up, and it pulsates in a very chorus-y, vibe-y way.