Don't worry about being the bearer of bad news. I should have been more diligent myself. I think it was a bit of me having rose coloured glasses as well. I really wanted ARB's so when these came up I was all over them.
It was an odd deal because I didn't actually buy the diffs directly from him.. He'd sold them to someone else but they were still on his Jeep... and the guy who "owned" the diffs got tired of waiting or something so he sold them on to me. I then ended up picking up the rest of the lift etc directly from Steve. LOL took me months to actually get everything as his Jeep sat out in Crossfield forever before it made it to Evolution.
I've been trying to find any info I can on the servicing of ARB airlockers and it appears they aren't insanely complex. I'm still hopeful with some attention and care they'll do the trick for me.