This is a description the stages in a restoration / annual maintenance presented in a logical manner. Needless to say GRP Mirrors need less maintenance than wood, and the amount of time you have will vary, so you can just pick articles to suit your circumstances.
I am all in favour of seeing old wooden Mirrors restored back to good condition. In a way, a restoration is just annual maintence writ large. It does take quite a long time, and, given the current (2018) market for second hand wooden boats, the result probably won’t fetch a high price if you come to sell.
It can be difficult or even impossible to restore water damaged ply back so it will look good when varnished. If the inside of a boat’s buoyancy tanks were not thoroughly painted or varnished when it was built, this is likely to be a source of problems until it is sorted out (and to do this you have to take the decks off, which is really difficult).