The evolution of #4 is somewhat of a mystery after WWII. Most of the people I've talked to who plaed the pre-Fazio course thought they were playing the Ross original. They weren't. They were playing the last iteration of Rees Jones' work. I believe Rees brought the lake into play by stringing the 13th and 14th holes along its bank. Hanse kept them with few changes - although I like his improvements to 14, better visuals, longer and a more interesting green. But make no mistake, #4 is a Gil Hanse course. Shadows of the Rees/Fazio course are there but it is a completely fresh take on the property.
The following is a CliffsNotes version of the evolution of Pinehurst #4 in the 1950s-60s:
Robert Trent Jones was brought in in 1950 and he created a new nine hole course that utilized the 1st, 2nd, 3rd, 4th, 16th, 17th, and 18th Hole corridors of the original Donald Ross #4. The first four holes utilized the same routing as Ross, with the first two holes (a par 4 and par 3) playing down what is now the par 4 first hole. The third and fourth holes of this course played through the same corridors as what is now Holes #2 and #3 of the Hanse course. A new 85 yard par 3 was created to serve as the 5th hole that played generally from today's 15th Tee toward the fairway in the same direction it plays today. The 6th Tee then played from there to the current 16th Green. RTJ took Ross's original par 5 17th hole and created two par fours out of it, the 7th and 8th Holes, playing west along Morganton Road. The 9th hole of the RTJ course was today's 18th.
In 1953, #4 was again expanded to 18 holes by Richard Tufts, but the portions of the original Ross routing that were taken out of play in 1950 were not used for the expansion. Instead, the new back nine was comprised mostly of holes from what was then the front nine of Course #3 and what is today Course #5. The 10th Hole was a par 3 that played generally from what is now the 7th Green to the 6th Green of The Cradle. 11-18 were across Beulah Hills Rd. 11-13 played through the same corridors that was then Holes 2-4 of #3 and is now Holes 2-4 on #5. The 14th played from behind that green to what is today the 14th green of #5. The 15th was in the exact location as Hole 15 on #5 today. The 16th was a par 4 that played to the west through what is now homes and condos to a green that was located somewhere near the present Hole 17 tees on #5. The 17th and 18th, then, played down the same corridors as what was then Holes 8 and 9 of #3 and what is today Holes 17 and 18 of #5. This, of course, disrupted the original #3 routing, so Tufts also built nine new holes for #3 at that time.
In the late 50s-1960, Tufts decided to expand the resort to five courses, so the 5th course was built in 1960. However, it wasn't built as one contiguous eighteen, but instead as two separate nine-hole additions to Courses 3 and 4. There is disagreement between the Tufts and Maples families over who designed the first nine; some say Ellis Maples did, others say Tufts designed it and Maples constructed it, but it comprised what is now Holes 5-13 on #5. Course #4 was also re-configured at this time, with the second new nine, designed by Richard Tufts and his son Peter, on generally the same land as Holes 5-15 of the original Ross course, though with considerable changes to the routing. The creek on the original course had been dammed by 1959 (and possibly earlier), though it was smaller at that time than it is now. The expansion to its current size appeared to happen sometime between 1960 and 1978.
The routing of the new #4, then, played along Holes 1-3 of the Ross/RTJ course, before veering off at Hole 4. The fourth hole of the Tufts course played north through the same corridor as Hanse's new 5th hole. Hole 5 played north-east from what is now the 6th tee of the Hanse course to somewhere in the vicinity of where the 11th tee is now. Hole 6 was a par 3 that played from there west to the present 7th green. Holes 7-9 of the Tufts course played generally in the same direction as the new Holes 8-10 today. Hole 10 was much more of a dogleg that it is today, though it does play to generally the same location as today's 11th green. Hole 11 was in generally the same location as the 12th hole today, playing along the north side of the lake to a somewhat peninsula green. Hole 12 was a par 3 that played from today's 13th tee to a green near, but behind, today's 4th green. At that point, the course picked up the RTJ course again, with Holes 13-18 playing what was (from 1950-1961) Holes 4-9.
I could probably go on all day about the further revisions to the course by Jones/Fazio as I love exploring this kind of stuff, but that's probably enough detail for now. Much of this info was extrapolated from some really cool aerial images/routing diagrams in Richard Mandell's book
The Legendary Evolution of Pinehurst, which you really should read if you have any interest in how golf came to be here in the Sandhills.