Nothing to add to the shirt query but no-one seems to have commented on the introduction of staybrite/anodised badges and buttons. Later than 1960, certainly. I went to the far east in March 1967 and was certainly wearing brass buttons up to that point, as were my airmen.
As a B/E in 1960/61 I have a vague recollection of staybrite buttons being available for purchase with the cap badge coming later. Our uniforms were referred to as Best Blue (T63) or Working Blue (with jacket not battledress style). Battledress was issued later on leaving St. Athan IIRC. No one ever referred to them as No.1s or 2s. These numbers usually described ones intention when going to the bogs. The Best Blue, if memory serves, was of something called Barathea (Sp)