I do not have the Gaggia coffee deluxe but I read somewhere that it has an aluminum boiler. Some people recommend using tartaric acid instead of citric acid on those (citric being too harsh).
Anyway your grinder from another post looks to be a Gaggia MM. Im not sure how you find the grinds but a lot of people say its not really up to making good espresso. I have the Gaggia MDF which is a step higher than the MM, and although its built like a tank I actually wish it were stepless sometimes.
Good luck restoring your new toys :)