I don´t know the gun or the dealer. I´ll try to translate the text:
The dealer describes that the first 20.5 cm (8") are stronger than the rest of the barrels to bear higher powder charges.
Condition of the gun is fair, inner barrels clean, stock has a little failure at one end, locks well working. The gun is in good shooting condition.

I hope this will help.

Regards,
Jörg