Unless something has changed in the last 10 months since he retired, a member of my church who was with HPD said old-timers who had been carrying various previously approved guns can continue carrying them if they can continue to qualify with them. He, for example, has a Smith 4006 and his partner had carried a Smith model 19 revolver for years before switching to a Glock 22 about 4 years ago. After he retired he went to work for a local County Constable and he's continuing to carry the 4006 even though he owns a brand new G22.
For what it's worth...
Q