Thank you for the generous comments gentlemen.
My eyesight isn't too flash, but I've discovered using a dark block shade - and then the main colour on top, leaving a little of the dark shade showing around the 'edges' (especially on cuffs and other facings), tricks the eye (at least from a distance) and blurs the boundaries between each colour. This 'hides' the bits where my hands weren't too steady or my eyesight let me down. Hence the description of my style as "impressionist". My brush work is no where near as accurate as some of the fine work other forum members have posted here.
Incidentally - I'm a white undercoat man. Especially for white uniforms - which brings me to Greystreak's comment -
Nice looking unit, John! I think you've got the 'contrast' between white/grey spot on with these!
Very kind of you to say so! Yes, I like my white uniforms to have a slightly offwhite, dirty, "we've been marching miles on the dusty summer roads of Europe" look, rather than a straight white / dark grey shading effect. I think the base shade coat I use is Vallejo 'German Camo Beige' or something like that, worked up with increasing amounts of 'Bone white' (Vallejo Game Colour range) and straight white (but I never apply the latter neat). Besides - the experts all seem to agree the Austrian rank and file uniforms were an off-white / grey-ish shade anyway - so I'm being Mr Authentic