Teak, especially old teak, is hard to positively ID from photos. It does have a very distinctive smell when cut however and if you’ve ever smelled it you will always remember it when you smell it again.
It looks like this could be teak but as I said… hard to tell. If it is it’s a great score. The stuff is like gold, even was back when I was buying lots of it in the eighties.

The early bird gets the worm but its the second mouse that gets the cheese.