The AZB prefix would put the gun in the first half of 1988. As you probably know, the no-dash and -1 586s were recalled due to problems with metal from the primer cup in some loads potentially flowing back into the firing pin/bushing area and causing the cylinder to bind. The -2 incorporated the new firing pin and bushing design, so was not subject to the recall. SCSW doesn't mention any other changes between the -1 and -2.
On a side note, I've always had a soft spot for the 586 and currently have three of them, along with a couple 686s. Yours looks to be a real beauty.
NRA Benefactor Life Member
Pemigewasset Valley Fish & Game Club