Great job Andy. Regarding Milliput; sometimes, it can be rather stiff to knead and work with, possibly just the 'batch'. My current box is a bit like that - hard to get going at first. But, the more its' kneaded, and as it gets warmer from handling, the softer it gets. It won't get quite as soft as putty used in window fitting, but should be easier to handle and mould. To give a smooth surface for finishing, or help to mould it into position, or into cracks etc, just wet it slightly, or use the back of a scalpel blade, wet.