The blade seems to have had a fair bit of use, and from photo 1 appears to be pre laser cut saw plates.

Must admit I have never personally seen a saw blade with alternating teeth at different rake angles, well not knowingly at least. It would be interesting to find out more about the blade.

One thought that has crossed my mind - I wonder with the neutral (or slightly positive) rake on the cutter teeth and positive rake on the FZ tooth that it came off a large radial arm saw?