8s was offered in both the original "pointy top" levers and in the later, post 2000 style more rounded levers.
Technically there were two versions of the 1993-2000 lever, the earliest ones without and later ones with, a helper spring at the back of the lever assembly. The ones without the helper spring are all 8s. Those with a helper spring were offered in both 8 and 9s. The internals were all interchangeable between levers of this generation in 8 & 9s, but not with the "non helper spring" version - here there was limited interchangeability.
The carry over into the rounded-top levers was on 8, 9 & 10s versions.
Until 2002, the internals in all these levers were interchangeable with a couple of small variations, according to whether the internals rotated on a brass bushing or ballbearings.
In 2002, Xenon and Mirage changed to a different system (Escape) in the 9s versions. This was later expanded to 10s as well.
If the first click on the lever is "soft" as Jonnyboy666 suggests, then yes, just clicking through the index stops with no cable attached or with minimal tension on the cable will show only 7 apparent clicks and the indexing will be all over the place because you won't be correctly pre-loading the tension in the RD spring.
On the other hand, at the SC and in shops across the land, 8 and 9s levers often got their internals swapped around and used levers from EBay etc are frequently levers that have been serviced, modified etc - we see a lot of them at the SC where we can tell they don't have their original cable ratchet bushings in them.
The cable ratchet bushing, which in all levers except Escape-type (or much more recently, 2012 onwards, PowerShift-type) is the part that sets the indexing (it's the part that the cable is anchored into) is labelled. Unfortunately, the marking faces "towards" the rest of the assembly when it's in place and can only be seen on removal.
Put simply, if there's no marking, it's 8s. More recent ones are marked 8, 9 or 0 depending on 8, 9 or 10s.
If a "click count" isn't, for any reason, definitive, then stripping this part out and taking a look will tell you for sure if the lever internals have been swapped around.
Last - remember that in 2000, Campagnolo changed all the lever pull ratios, relative to the RD. If the RD has a B Screw, it's the old type, with a different pull ratio to the later ones where the relative tensions on the upper and lower pivot springs were set by the "H Screw" on the jockey cage. The later version RDs do not index correctly with earlier lever versions.
