Peter:
I can tell you that the hole sequencing has never changed-- both routings are as they were on opening day. Interestingly, while the West has been considered the "longer" course for decades, I recall that some tees had been added to the East prior to that Shell episode, stretching it beyond 6,800 yds. Once upon a time (1923), the East measured 6,631 yds, the West 6,697. The West had been lengthened to 6,771 by the time of the 1929 US Open, and it has essentially continued expanding since.
Growing up in the immediate vicinity, I can recall frequently being told that the membership was more or less evenly divided as to which layout they favored. For me it was always the East, which offered a bit more variety and some truly remarkable green complexes.
I had the opportunity to discuss this subject at length with the late Dave Marr a few years back and at the very least, he certainly enjoyed the East equally to the West. Citing the severity of a number of green complexes, he said "When you miss a green, the West is a bogey course. The East is a double bogey course."
Additionally, I mentioned that Tom Doak only rated the East a six, saying that it "is sorely lacking for great holes"-- to which Marr, without a moment's hesitation, replied: "Ask him if he kept score."
He was the greatest.
DW