Hairline scratches usually make the record sound like youre frying bacon on it, and usually cant be gotten rid of totally.
I can recommend you give all your records a good clean with a dilute mix of washing up liquid (fairy) and fairly warm water. You will need a mega soft cloth too, which has never been used before (otherwise it may have gritty particles in it).
Fairy works becuase the crud in record grooves is mostly dried in grease from your hands......and as you know, fairy gets rid of grease
.
If theres millions of tiny scratches over the surface of the vinyl, Im not sure anything can be done about that unfortunately.
See ya
Sirius.