Define USE_GUSI2, not USE_GUSI1. PythonStandalone still doesn't compile due to tk issues, though, but it isn't important right now.
diff --git a/Mac/mwerks/mwerks_nonshared_config.h b/Mac/mwerks/mwerks_nonshared_config.h
index e3d97ec..446e2d4 100644
--- a/Mac/mwerks/mwerks_nonshared_config.h
+++ b/Mac/mwerks/mwerks_nonshared_config.h
@@ -5,8 +5,8 @@
** specific features, you may also need different sets of sources.
*/
-#define USE_GUSI1 /* Stdio implemented with GUSI */
-/* #define USE_GUSI2 /* Stdio implemented with GUSI 2 */
+/* #define USE_GUSI1 /* Stdio implemented with GUSI */
+#define USE_GUSI2 /* Stdio implemented with GUSI 2 */
#define USE_MSL /* Use Mw Standard Library (as opposed to Plaugher C libraries) */
#define USE_TOOLBOX /* Include toolbox modules in core Python */
#define USE_QT /* Include quicktime modules in core Python */