Ive been following on the Glock forum about this and how now the Glock factory will cerakote their frames in house. They then send the slides to Lipseys or other companies for cerakote, then the slides are returned to Glock for reassembly. Warranty is intact. Full disclouser, I do not work for Glock or Buds.

You won't find a factory Cerakoted Glock. They use a nitration process for hardening and corrosion resistance(Called Tenifer). The silver plate has the serial number and will not be coated as the frames are just a different color polymer.