How good are the older Leupold BR scopes with the locking AO ring ? , a local shop has one I am interested in, it is in excellent condition with the original box and all accessories, previous owner sent it in to Leupold about a year ago for service and they have the paperwork from Leupold as well, this scope in question was made in 1992 according to the serial number. Do these hold POI well? Thanks.