Help! Measurements worked out, but there's a possible flaw in the decreases

[KLKing]

Help! I'm knitting my Uncle a sweater out of this pattern. He is 6ft.tall, and his sleeve length is 33.5" Inches. I think that means from the edge of neck, to wrist(over a bent elbow) He does not want the sweater too short. The pattern I have does not tell me the height of the man the pattern is for, but I'm guessing he is about 5-9".
  I need someone with a guy of my Uncle's proportions to measure and give me these important numbers!  He lives 2 hours away, and this will be mailed.  I am at the stage where I really need to know where the armhole starts!
Here's the pattern:

Plus Enlargements so you can read it~ Body:

(Sleeves and Finishing)

Finally, here's the  1960'S book it came from:

Last bit of info: I am knitting in the correct gauge, but using two strands of Lion Brand Fisherman's Wool, and a size 10 needle. This is a thick cold country sweater.
I will be extending the neck edges up into a turtleneck as well. This is a boat neck.
I plan to use circulars or DPN's then.
Anyone out there can help??? Thanks so much! K

[Tephra]

Hmm, well I'd guess you'd want to hem to underarm in the vicinity of 18 inches. It really depends on if he's a guy that has his height in his torso or in his legs. If he's the long torso sort that could go up as far as 22 inches.

[KLKing]

   He's got long arms and torso. Since the pattern says 19-20, My guess is to add 3 inches. But, with expensive yarn, I'd rather be more accurate,

[Mossie]

It sounds like he knows you're knitting him a sweater and it isn't a surprise.  If that's the case, I would suggest having him measure a sweater that he already has and likes the fit of.

[Tephra]

   He's got long arms and torso. Since the pattern says 19-20, My guess is to add 3 inches. But, with expensive yarn, I'd rather be more accurate,

Oh, I thought you were thinking of the torso length, not the sleeve. The pattern says for the torso 15.5" to the under arm on the largest size, that's what I was thinking should be at least 18".

Well, since you have the sleeve length from neck to wrist you just need to know your row gauge and how many rows are in the raglan shaping, that will give you the underarm to neck length of the sleeve. Since you're going for a turtle neck you're going to want to have that be couple inches longer with a few more raglan decreases. Subtract that from the sleeve length and you know how long to knit them before you start the shaping. In general, whatever you add to the sleeve should be added to the torso too, because of the way human proportions work out on average.

As Mossie suggested, maybe get him to measure a sweater or sweatshirt that fits the way he wants. It would be best if he measured a raglan since then he could also measure the raglan length, but any style will do as long as the neck line sits where you would start a turtleneck. You mostly need sleeve hem to neck, back of neck to body hem, and under arm to both hems (and across the body from underarm to underarm wouldn't hurt for completeness sake).

[KLKing]

 Thanks Mossie and Tephra! I think you're right about having him measure something that fits.   You're also right that it isn't a surprise! He's been begging me to make it for 2 years now, and even sent money for yarn... But forgot to write a note what the money was for and my Mom spent it because the envelope had her name on it!  A few months later, he was
having a fit..." Where's my Sweater?" He's 74 years old and moving up to Washington State soon. He's also cold all the time. I guess I better call him again to get measurements.  I was hoping someone had a man hanging around with the right body type! LOL!
  Thanks again for your help!

[Mossie]

I love him a little bit right now.  I know a 92 year old woman in possession of a leprechaun green, wool, aran style sweater that she wears near daily year round, even in the high humidity, upper nineties, Virginia summers because she's always cold.  She would be cranky without it and I hope your uncle enjoys his sweater when you're done with it.

[soozeq]

The 33½" Sleeve length is from the center of the back of neck to the wrists. This chart should help you a little - http://www.craftyarncouncil.com/mansize.html - but these are actual body measurements, not finished knit sizes. So for the chest you'd want about 4" larger than his chest actually measures, and you'd want the sleeves longer. Measuring a similar sweater he already has is a good idea and better than measuring the person because it's hard to know just how far up the underarm to measure for the body and sleeve length.

[KLKing]

 Thanks everyone... I'm on the lookout for a neighbor to use as a fit model!
My uncle is too far away, and he doesn't know how to measure.
Thanks for all the advice!

[KLKing]

 Ok. Now I'm at the decrease part, to start the raglan shaping. I have both sleeves on the needles.  The pattern reads:(RE Back shaping)- use same for all sections, but it appears that the decreases are all slanting the same direction. I think a different decrease stitch should be used so the stitch direction changes on the opposite sides of each panel. Does anyone have any experience to help me with this? I'm reading this as a possible pattern error.
Thanks, Karen