Recently I was able to "collect" a pre-bonsai from a neighbor doing some new landscaping. He had already dug up some old shrubs, pretty nice trunk size that I thought might make interesting long term project. But I knew it was a long shot- they had been ripped out of the ground with no regard to saving a root ball....and they were pretty scraggly...but nice trunk and lower branch structure. Took it(Ithink it is Ixora, similar to Azalea) home and soaked in water with SuperThrive for 48 hours, cut off the obvious branches, put it in a large (12") clay azalea pot with a soil mix 50% volcanic cinders, 50% organic tropical citrus mix. At the time I could tell the foliage was stressed from lack of moisture, so I have been keeping it moist, and misting the leaves, with limited sun exposure. But, it looks like all the leaves are browning and going to drop....
So, my question is, in an effort to save it, should I severely prune back to the main branches I would like to save, or, should I go ahead and remove the leaves, or should I just be patient and let it progress naturally...?

Thanks for any input!