I have been offered a second-hand piano for free, I'm going to look at it at the weekend. Does anyone have any tips what I should be looking for (that might not be immediately obvious)? I have grade 8 piano, but it's not my first study and I don't know much about the internal workings.

Any tips appreciated!

Take a tuner with you?

Yes, Fen is right. take a tuner with you. I'm doing exactly the same thing at the moment, and have discarded 3 pianos already. I don't play, so I have a bigger disadvantage than you. Be very careful - I've found that people giving pianos away usually cannot sell them as they are worthless, but there just might be someone wanting to give away thier beloved instrument to someone who will care for it and play it - hopefully that's the case with you. The tuner / technician I have been using is charging me £10 for local journeys, or £20 countywide, so it's excellent value. And I've learned a lot about pianos along the way!

Good luck - hope it's a good one!