Hoping for some advise. I have an old Canon 100-400 which I simply adore, however I have noticed some specks which appear to be inside the lens. I have since heard that this lens is known as a 'Dust Pump' due to this issue. Anyone else heard this? Regardless, I am hoping this can be cleaned. I am in Plettenberg Bay and I know there is no one here that can do it but my partner is heading up to Jo'burg next month so can anyone recommend somewhere that can clean my old faithful for me?