Taking the mast down, what should I add to the top?

[ash2020]

Check the condition of the masthead sheaves and the running rigging.

Yes, I certainly will do. We're having to have a survey so the surveyor will probably do that too.

It all depends on how much you want to over complicate a 27-foot boat and the sort of sailing you do.

VHF, Windex, and a tricolor only if you sail offshore at night (inshore and in harbors and rivers, rail lights are probably more visible to nearby boats). Anemometers and wind indicator are only worth the trouble if you are fitting an autopilot that talks to them.. which you do not need.

Needs vs. wants. My PDQ has a bunch of stuff up there. My Corsair F-24 just VHF and Windex, and I wouldn't want more weight or windage.

I think you're right. We don't do much night sailing at all so the tricolour is probably a waste of money. I guess simple is best. Thanks, I was getting carried away.

 

[MADRIGAL]

A VHF aerial; if for no other reason than to deter birds.

How about a strut or crook for flying the burgee above the masthead? Also good for deterring birds.
https://www.royalthames.com/getmedia/8535596b-4e09-46e9-bfa2-d1cc54d095b2/Masthead_Burgees_2.aspx