Your Parker-Hale 1200 looks like about a late-1970s/early-1980s model due to the recoil pad and the satin finish (earlier Parker-Hale rifles had black plastic buttplates and high gloss finishes). There is no Parker-Hale serial number registry as far as I know. Your rifle was assembled in England with a Yugoslavian action. The bolt movement when the action is open is typical of a Mauser 98 action.
This is a very similar rifle to the later Mark X Mausers (same action and barrels, different stocks).