coat hanger math (or perhaps I should, someday, invest in a scale)

this is an attempt to figure out if I'll have enough yarn to finish the striped sweater.
above:
on the right: the finished "body" of the sweater. (I undid the 10 stripes of a sleeve that I'd done in preparing to rip the whole thing out). On the left: an assortment of full skeins of yarn that totals 500g.

so, figuring that two sleeves is about 2/3 of a sweater body (I wrapped it around my arm and then doubled it and 2/3 was the best I could do), I put 325g (2/3 of 500ish) in the bag on the left (thank goodness for my occasional novelty skein that is 25g instead of the usual 50g). The yarn I have remaining for the stripes is in the bag on the right. It's not going to be enough for two long sleeves.

The same ~325g on the left, and I added 75g to the remaining yarn on the right. It looked just about even to me, and so I need at least another 75g to finish.

the same 325g-ish on the left; the right is the remaining yarn with the skein of brown fleece I picked up yesterday (100g). This looks even too, and the math is easier with 100g. (stay with me, I think it'll make sense...) SO: I need 325g to make two sleeves. 100g of the 325g is all one color; the other 225g is made up of seven different colors. In order to make this work, I'm going to have to have a ratio of 2:1, old stripes colors:new purple. This means that I'm going to need to fit two seperate stripes into the seven color pattern, or I'm going to need to break up the seven color striping with 4 rows of solid striping. Any thoughts on what would look better? (and does this make sense to anyone other then me?)

please ignore the not-so-organized bookcase in the background; "fun" reading hasn't been a priority for awhile!