Hello Steve,
even using resistors of utmost precision you would neither obtain a 600 ohms input resistance (= load resistance for the TG) nor a 50 ohms output resistance (= source resistance for the 50 ohms load).
You may verify this fact by terminating the output into 50 ohms and measuring the resulting input resistance (which will be 575 ohms). Terminating the input into 600 ohms (= source resistance of the TG) will yield a source resistance of approx. 47.916666 ohms for the load.
Regards
Martin