Maxi cosi pearl car seat (Brimscombe GL5)

I bought this secondhand about 4 years ago. It is in used but completely functional condition. It is the type that has a base with a stabilising leg. It has isofix. Forward facing only. 9-18kg. The arm straps have some mould stain as shown in picture. This has been scrubbed and cleaned with antibacterial spray but refuses to come off. The leg folds under the base for storage. The seat has three positions to sit up or back