When you have two weak but playing notes in an accordion it normally indicates a problem with voicing. Years of playing cause the opening (height) between reed tip and reed plate to decrease, causing the sound to weaken and the reeds becoming more prone to choking.
Whether Chinese rubbish reeds behave like good Italian reeds I don't know. But an accordion repairer should be able to fix this, maybe with the original reeds, but maybe by replacing the reeds.
A Scarlatti is a cheap Chinese accordion, acceptable for initial practicing for maybe a few years. If this accordion already survived for 7 years without falling apart, count yourself lucky. The problem can certainly be fixed, but you have to consider whether the repair cost is worth it considering the value of the accordion. You may get lucky as it's just two notes that are a problem now, but who knows how it will go in the future...