I'm surprised Pete has not been in and commented on this yet, recycling old timber is his thing and I'd have thought this was up his street.
I must be something to be trusted to work with a piece of history like this, you've done well and I hope that the gift is properly appreciated.
Truthfully I thought I'd recognise teak, fresh cut or silvered with weathering, but I would never have recognised this as teak, the colour variations in it are beautiful. I've only worked with Teak as carpentry work, not turning but understand it is fairly hard on the cutting edge due to the silica content, but this piece has been to sea, so there will be salt soaked into it making it even harder to on the edges. How was it to work?