UKHKA 18 Knitting Pattern in 4 ply Baby Jacket & Helmet Sizes Prem - 12m

UK Hand Knitting Association Knitting Pattern in 4 Ply yarn for a Baby's Collared Jacket & Helmet in sizes:
Prem: 31cm (12")
Newborn: 35cm (14"),
0-3 months: 40cm (16")
3-6 months: 45cm (18"),
6-12 months: 47 cm (20")
 
Recommended yarn quantities, based on average requirements: 
 
For Collared Jacket : 4Ply 50g balls  x1 (2:2:2:3) 
For Helmet: 4Ply 50g balls  x1 (1:1:1:1)
 
3.25 and 2.75mm knitting needles
For jacket: 6 buttons