Trogdor, it is absolutely still possible for you to hand train him/her. Let him get used to his new digs, then start training him. You will be able to tell when he gets comfortable because he will start making happy noises and will eat and drink in front of you. During this time keep talking to him and playing music if it is going to be quiet. Quiet worries them because it means a preditor is in the area (at least in the wild that is what it means).
The main thing to remember in hand training is patience. Some train quicker and easier than others. Just go at his pace but dont give up if it is a slow go. It is worth the time to have a hand trained keet.
There is some excelent instruction on this web site on hand training. The first step is him gettin used to your hand in the cage.
Here is the url for the training guide.http://www.lisashea.com/petinfo/articles/bird_hand.html
There are many ways to train you budgie but this one is very good. It is especially good if it is a new young keet.
Good luck with your hand training. You may even be able to convice you older keet to take to training