want to trade 7" stainless tank bands for a pair of 8" tank bands

[Gravybird]

I was sold a used pair of tank bands at a dive shop as a 8 inch pair, and they even measured 8" with a tape measure, but they just don't fit on my LP95's

once I do get them around the tanks, there is just barely enough room for the bolt to slide through in between the tanks. It just doesn't feel right, however, I have no experience with this
How close together should a set of lp95's be when they are banded together?

I imagine there is a price difference between 7's and 8's... so I would be willing to cover a reasonable difference