Win&Win Limbs Serial Numbers

I have just purchased a second hand pair of Win&Win Inno Ex Power limbs.

I noticed that each limb has a different serial number! I checked another pair of SF limbs and they have the same serial number on each limb! I have emailed the supplier with my query.

I thought that pairs of limbs had the same serial number. Is this a mismatched pair (mixed up pair of limbs). I set my tiller bolts out the same distance on my Fiberbow TX riser. Checked the tiller and got +8mm.

Any answers to this?

Thank you