Ok, I'll resize for future pics.

First run of the duplicator
Aaand it was a disaster. Good thing that it was only some cheap Macrocarpa.
Still, a few lessons learnt:

1: Watch your bit to make sure that it doesn't move in the collet!
It had gone about 1/4 inch in the collet before I noticed, with somewhat... bad... results.

2: Find a better way to index the blank to the pattern
One side was pretty close to the roughsawn.

3: Put a 100mm spacer in each end instead of 50mm, at least until die grinder is fitted.
The mounting bar and collar that the router goes into interferes with the faceplates.

The die grinder I'm getting has a long, narrow neck that will put the bar and collar well above the collet and bit.

As it didn't come with instructions, I'm having to learn as I go along. All good fun.