I was teen/young adult in the 80’s and was already then bitten by the intarsia bug. Unfortunately very little documentation has survived recent decades, but my profile photos has one snapshot of my Milou sweater, that was fully engineered by me. Charted by hand from a comic book photo and then knitted from some mill end yarns from a nearby lys some time in the late 80’s.
I enjoyed this knit very much and even more after I started ’doing my own thing’ with the ’vleks’.
Used long tail cast on, casting on into a 3+2 ribbing instead of row 1.
Used knit f&b for the increases for the sleeves.
Weaved tails in after blocking, but knotted some tails together to keep tails from too much ’slacking’ during knitting.
Instead of bobbins I use techique that combines ’loose yarn mess’ and has an occasional ball in there somewhere. I really don’t mind untangling my ’loose mess’ after a few rows. Pulling shorter yarns free from the ’mess’ helps to untangle the few balls in use. In general the type of sock yarn used here does not make nasty knots easily.
17.12.2022
Planning to swatch during holiday and only cast on after. Haha, that plan never works out for me 
18.12.2022
Swatched and even blocked the swatch. Result; my gauge with 4 mm needle is about 10% tighter, but the fabric with this yarn is good. I don’t want to change to bigger needle.
With my gauge size 4 stitch counts should result slightly smaller than size 3 given measurements.
Starting with size 4 and will rethink this after some knitting of the back piece has happened.
20.12.2022
Adding one basketweave repeat to body before starting the shaping for shoulders.
20.12.2022
Finished back and it is blocking. Decided to try to be creative with some of the front ’vlek’s.
Finished measurements 51 cm wide and 55 long.
25.12.2022
Front finished. Difference in photo is from blocking. Blocking front tonight.
28.12.2022
Sleeves will be blocking overnight.
Working the neck ribbing. Only half of the rounds in the pattern and then sewn tubular bind off.
29.12.2022
Paying careful attention to small and even stitching in shoulder and upper arm seams. Side and underarm seams will not show, so stitching those will be done with much less care 