KathyP:

You may want to transfer more Amex points and/or buy the points necessary to get to 425k.

Your plan will net you a max of 240k miles (Marriott will refuse to deposit more than 60k, regardless of distination). You will have 100k points in your account left over after redepositing the two 7-day certs.

By ordering a 714 for 425k and redepositing the two 10-day certs, then ordering a 713 and redepositing the 7 day cert, you will get 360k miles, plus 62,500 points left over.