Just an update to this post.
We received 2 new cylinders from Divelife. If it wasn't for Brett I doubt we would have so thanks Brett!
Basically, even though we did everything correctly as it says on the tin so to say, because of the damage to the cylinders, Luxfer were saying it was dissimilar metal corrosion from the incorrect fitting of the stage strap and/or not rinsing and they would not be liable. How could we prove we did everything correctly! (How could they prove we didnt)
Lads, I can assure you there was no contact between the two metals. Even using the jubilee rubber, it was clear to see the pitting on the edge of the rubber.
So for those of you who do not rinse your bottles, I don't know how you get away with it!
I realise that there had to be contact for it to happen but this could only have been from the water droplets after use that was making contact from the stainless jubilee clip, over the rubber and onto the cylinder.
Maybe it was a freak once off case (with 2 different bottles owned by two different people) but there is a lesson in there somewhere!
Please check your tanks if they are of the unpainted/coated kind..
P.