i have bought a guitar on ebay. it is quite on old guitar (1985) and suffers from some cosmetic damage including rust (here).

should i replace any rusted parts or doesn't it matter and is only cosmetic?

If it was me, I'd change them. Mostly because it looks nasty, but I don't imagine rusted parts are going to do you any favours.
depends what it is. you could soak the parts in some anti-rust formula and put them back in. Depending on where the rust is you may wonder about how the guitar was stored and if there would be any other issues due to humidity.

rust on a bridge or pickups is sometimes due to sweat and grime.
welll.. if its rusted, that probably means its been around moisture for a while.. so .. id replace or restore all the parts of i could and.. maybe the wood it rotted .. but i doubt it
damn I like rust . Looks so rough & metal. But if you don't like it, change it.
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