Yep, it's screwed from the inner side, and cause the original handle is die-cast, there are no holes from outside needed.
Derek, the holes will be small at the outside, even if we cut the thread. Leaving this to the customer may end in worn out threads from the beginning, cause you need a good feeling with the material, if you cut the thread with the screws, not to use too much force on it.

And yes, there will be more batches than one, don't worry. But it'll take time.