In regards to the letter on powdered milk, the method described in the web site works, but does not produce milk that tastes very good (depending on the oil used).
Growing up all over the world we often were in places where tuberculosis (TB) was endemic in the cattle populations. As a result you could not drink milk but could drink/eat yogurt based products (the process of conversion to yogurt will kill off the TB). Of course to this day I always test positive for TB because I ate the yogurt — even though I don’t have it — as a result of the dead TB bacillus in the yogurt I developed antibodies to it.
As a result my mother researched how to make “real” tasting milk from powdered milk. What we found (and the method that was used by the military to reconstitute milk in many places even today) was that if you added one can of evaporated milk per gallon of powdered milk you got “real” tasting milk with a decent fat percentage. She also found that mixing the powdered milk using hot water (and then cooled overnight) actually made a major difference in taste.
The only time we tried the method described (using oils) was when the supply plane we and the rest of the mixed military/state department expat community relied on, was very late. To this day I remember the taste of powdered milk mixed with olive oil (the only oil available locally in Ankara at the time) — even with copious amounts of chocolate milk mix (Ovaltine) it was still nasty. – Hugh D.