This is an official tournament-used scorecard from the 1999 Shell Houston Open. This is Peter Jacobsen's final round scorecard featuring playing partner and marker Payne Stewart. Scorecard collectors often seek out marker scorecards since the scorecards are entirely written in the marker's own hand. So yes, almost all of the writing on this scorecard, including the hole-by-hole scores, was done by Payne Stewart himself.
This scorecard was kept by Payne Stewart on May 2, 1999. Sadly, Payne would pass away less than 6 months later on October 25, 1999. The scorecard contains an excellent Payne Stewart autograph on the bottom right.