First things first, the bogies were built as per the instructions, ensuring they were squared up correctly and the wheels sat flat on a glass surface. At this stage I did not add the coupler mounting strip provided.
Before constructing the body I made openings 3mm x 11mm in the headstocks on either end - this will allow the coupler to swing as the bogie turns, as seen here on the completed adaptation:
The modifications to the mounting strip were all made before it was fitted to the bogie and can be seen in the diagrams below....
Fig 1 - Cut the end of the mounting strip 11mm from the centreline of the hole that fits over the bogie (approx 14mm from the end of the part).
Fig 2 - Shape with a rat-tail file a semi-circular indent into the end of the part - this is to allow the MicroTrains 1015 coupler to work correctly (under pressure it pushed back out of the draft box).
Fig 3 - a) Add a 20 thou styrene shim 8.5 x 5mm under the mounting strip and level with the cut end - when set shape this with the rat-tail file to match. b) Cut a 40 thou styrene piece 6.5 x 5mm, adding a taper at one end over about 1.5 mm. Fix this in place and once set trial-fit both the mounting strip and wheelset, if need be use the rat-tail file to create extra clearance.
Once this has all set, drill a 0.9mm hole on the centre line in the exposed 40 thou platform, 2mm from the front edge (check using the draft box to locate exactly). Effectively 'tap' this using the MicroTrains coupler screw and clean up any excess styrene burr. Optional at this stage is to shape the end of the 40 thou piece to make it less visible underneath the coupler when fitted. The mounting strip can not be stuck to the bogie:
This view shows how the bogies look once fitted with the wheelsets, the clearances are rather tight but the bogies remain free rolling. You will need to shorten the MicroTrains screws for the final fitting - I used a razor saw with the screw held in my desk vice:
An overall view of the completed (unpainted) coach with the bogies and MicroTrains couplers fitted: