Stagecoach North West (that's Chorley, Preston, Lancaster, Kendal, West Cumbria and Carlisle depots) store most of their vehicles at West Cumbria's Lillyhall depot.
Currently there are around 15 Leyland Olys stored there, some Volvo examples and many B10Ms.
Morecambe has 5 stored Olys and about 10 B10Ms.
--- old post above --- --- new post below ---
Re-reading your post, I see you want newer than 1992. There really aren't many of those Olys around:
16327/8 (N327/8 NPN) date from 1996, as does 16340 (N340 NPN). It's unlikely you'll get them though as really they're only in between homes.
The only other stored Volvo Olympians are 16294, 16329 and 16393 which are all open-tops for summer operations.
HOWEVER....if you don't mind older than 1992, there's plenty of choice: 4 Leyland Olys from 1988, 2 from 1989, 2 from 1990 and 3 from 1991 are reserve/disposal.