The poor grade plating is removed by immersing in bleach. Use 2 gallons at a time and change solution(scrub and hose off between changes) every 24 hours . Takes about 20 gallons to clean. Broken pieces can be joined together by (using a small artist brush) applying Acetone to both edges of break and then pressing the pieces together. Acetone acts as a solvent to the ABS plastic making a more perfect bond than glue. If you have chips or holes to fill you can make a putty like filler by soaking ABS shavings in Acetone.
Final finish is up to you but I have had good luck with Enamel Model paint.
Final finish is up to you but I have had good luck with Enamel Model paint.