Smart - even a regular chap in the 1940's wouldn't
have dreamed of leaving home without a collar on, or a tie. He might
relax at home without a collar, but stepping out in public, he'd have
been properly dressed. Spearpoint collars were common, but not the
only type of collar worn.
Shirts, ties, waistcoats, trews, jackets (if
you can get one to fit) suits, polished shoes, neat and tidy. I personally
find modern day 'dress down' disappointing, as a gentleman looks so
smart in a suit. Hats and gloves were also a part of the ensemble,
but not always.
If you are dressing in uniform, make sure you have the details right
for the type of person you want to portray. It is all about the details.