Hi Brown, First of all, it looks like your understock is doing the leafing out. That is the portion from the graft on down. If im seeing correctly it is your lower portion with the green bark. If that is so and you can see the graft union...carefully pinch those off. Again if i am seeing correctly, the ggw leaves look like they havnt unfurled yet.
Lots of hope for that little tree.
As far as an 'Aureum' is concerned maybe you should try an online source even though its not the most ideal time of year, its doable.

Al