The latest update shows how I have used 3mm thick plastic card to build a lid to the crew compartment and a larger buffer or bumper to the lower hull.
In the case of the crew compartment roof - it was a simple matter of supergluing a strip of 50mm wide, 3mm thick plastic card to the top of the upturned hull and then trimming it back to fit the hull. A thin layer of Milliput hid the join and I used a sanding stick to sand the roof to shape and a fine nail buffing pad to smooth out the sides.
The lower hull buffer or bumper is something that I have seen on many Ma.K hover tanks - I cut 3mm thick plastic card in the shape of an iron, making the edges 3mm wider than the hull profile. I then sanded the edges in to a half curve shape and glued it in to place with more superglue.
The join between the buffer and lower hull has been detailed with watered-down Milliput, smoothed out with a wet brush and finally sanded smooth once fully set.
The main hull shape is now developing well and coming along quite quickly.