Linda, there are some marked "R" and others marked "MR". The Sweet Sixteen needs just the "R" ones.
I agree all the numbers are confusing. Here's a photo of my Groz Beckert needle packages. The size is on the righthand side of the second line. I paid $35 for 100 needles from the eBay seller mentioned earlier.
[ATTACH=CONFIG]454860[/ATTACH]
Daffy