Help with "Crescendo" pattern

I’d like to make this shawl, but I have a question about what size needles.

First–about the needles. The pattern states that you are to use a worsted weight yarn, but use size 13 needles. Now since this is a vintage pattern, do they [I][U]really[/U][/I] mean size 13 (that is, 9mm), or do they mean something else? Worsted weight yarn typicaly uses somewhere between sizes 7-9 (4.5-5.5mm) needles, though I realize that the size needle will need to be bigger because the shawl’s fabric must be drapey.

Okay, now what about the gauge? They’re telling you to cast on 100 stitches, so will this work out to be the right width (the 19")?

As far as the needle size, I’d go with whatever it takes to get gauge. One cable should be about 1.24 in. To test I’d cast on 12 sts and do one repeat of the 6 st cable. The shawl doesn’t look particularly drapey but it might be calling for a larger needle since the whole thing is cabled…cables done with a needle that is “regular” size for the yarn look much tighter than those do…

Try it, you’d be surprised what using large needles with worsted looks like. Though I do have some older worsted yarn and it’s thicker than what’s being called worsted today, but I think it would be fine. Do a sample of it - CO 28 sts (multiple of 6, plus 4 for the edge sts) and work about 2 pattern repeats of it and see how you like it. It’s a shawl, so it doesn’t need to be knit as densely as a sweater.