But last night was our club's airgun night and the club owns an almost identical FWB 602. Comparing the two I noticed that the front sight is mounted differently on both rifles. And nobody at the club knew which was the correct way.

Which one is correct? And does it really matter? At the club we've been shooting that rifle for months very successfully, and with my rifle on a bag rest, I succeeded in getting a PERFECT 120/120 score at 10-meters on a standard air rifle target. I had not ever been able to do that with any of the other guns I own and I think this indicates the rifle is set up well.
So, what's the right way and does it really matter?