Check rigging and loose gear. Originally (60s, 70s, 80s) Mirrors were supplied with galvanised steel wire standing rigging which rusts & should be replaced. Check splices & generally look for signs of wire strands breaking. Avoid kinking wire rigging by keeping it loosely coiled.
Mirror running rigging from the 60s & 70s was utterly basic - 3 strand cotton sheets and hemp halyards. I would recommend replacing this, unless you are trying to maintain the original features of your boat. Ropes should be heat sealed or whipped so there are no frayed ends. Worn ropes should be replaced, and you may wish to replace some rigging to get better performance (e.g. modern low streach line for halyards & forestay tie, thinner jib sheets,..). See our running rigging guide for recommended thicknesses & rope types.
Burgee staffs should be checked for straightness & straightened if necessary. I use Falker burgees which have an effective counterweight, which work even if the boat is heeled, so a good idea to check you burgee balances correctly.
With rigging & loose gear washed & checked, it can be stored away ready for refitting.