Once the boxes were finally assembled the jig came out again this time the mystery four holes in jig and red circles were used to finish off the assembly.
The four holes are inbuilt carry handles and the red circles a predrill locators for the final screws.
I used countersunk climacoat 32mm screws, one in each finger joint.
The carry handles were radiused with a round over bit in the trimmer and then a coat of shellac applied.
OMG its back to cleaning up again !
-- Regards Robert