Here is a bytes type.  It's very minimal but it's a start.
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 914e0d1..54e8fe8 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2139,6 +2139,7 @@
 	SETBUILTIN("basestring",	&PyBaseString_Type);
 	SETBUILTIN("bool",		&PyBool_Type);
 	SETBUILTIN("buffer",		&PyBuffer_Type);
+	SETBUILTIN("bytes",		&PyBytes_Type);
 	SETBUILTIN("classmethod",	&PyClassMethod_Type);
 #ifndef WITHOUT_COMPLEX
 	SETBUILTIN("complex",		&PyComplex_Type);