If you get some J-B Weld SteelStik Epoxy putty it matches perfectly as the cracks are in a groove, and it cures Dark Gray in color. Home Depot carries it in the paint section @ $5.98. You have to work quickly, mix small amounts and do one crack at a time as it sets up in 5 minutes and cures in an hour. I just kneaded the 2 parts together, rolled it to a size that will fit in the groove, pushed it into the cracks in the grooves with my fingers and a toothpick, then scraped the excess off with the toothpick. You can't even tell where the repairs were made. No painting needed.
As far as the weak magnetics in the head, I just used two 1/2" x 1/32" Neodymium disc rare earth magnets to really strengthen the magnetic bond. I bought mine off of Ebay as I could not find them locally. I figured out the gap between the head and body magnets by cutting up one of those refrigerator magnets and placing pieces between the two magnets to make sure they would not create a gap in the neck area. All this was under 10 bucks. Hope this helps guys