Yes Jim, I purchased the book at Durban Airport, probably 3 years ago now, for around 500 Rand (50 USD) and agree it is probably the only book, that I can think of, which graphically depicts some of the better golf courses in South Africa - with a bit of information about these clubs as well. I question some of the newer golf courses being in this book particularly at the expense of some of the parkland golf courses in the Johannesburg area which are quite good. Perhaps, as Philip mentioned, this is because there is more of an association with new versus old.
Colonel SV Hotchkin (of Woodhall Spa + West Sussex fame) toured South Africa in the N.H winter of 27/28. His work would span the country and by the time he left he would have visited / been involved in many of the better golf courses we see there today. The spread includes Humewood, East London, Port Alfred, Maccauvlei and even Durban CC (from recollection) + a host of other well-known golf courses in South Africa. It is hard to argue that he probably had the most influence of any foreign architect.
I can see why East London GC is not a popular 'out of the way' stop. The city, whilst picturesque, has a real sleepy coastal feel about it and there really is not much going on - although I am sure the locals would dispute this. I visited over 15 years ago and remember the cricket team being quite good and friends telling me how good the surfing was but that is about it. Mercedes Benz (or was it Volkswagen?) had their head office and factory in East London and I think just about everyone was directly or indirectly effected by its fortunes.
Unfortunately I did not have the time to visit the club during this trip - which I regret. However I recall, because I drove past it once or twice, how much natural rise and fall there was and how dense some of the scrub bounding the holes were...much like you find on the first and last few holes at Durban CC. I believe it has seen a bit of facelift but am unaware how much of the original design has been retained ....certainly the bunkering seems to get lost in the scale a bit.... but perhaps that is how it was originally.
In terms of Humewood you are about right Tom. The routing does not impress that much although the back nine seemed to have a bit more interest than the front. Certainly, from recollection, there was more native vegetation/scrub separating the holes on the back nine - this gave each hole a bit more privacy - and was a great contrast to the front which was predominately very open. In addition to this the ground contours on the back nine were much more aggressive and certainly gave added strategic interest - see hole you mention. Other holes I remember being O.K were the 10th, 11th, 14th (Par 3?) and 18th. On the front nine I recall the short Par 3 (think hole 6?) and Par 4 hole before this. The SA Open was hosted at Humewood a couple of years ago now (Els won I recall) and some changes were made to the course including a rather bizarre stream running in front of the green on the Par 5 17th.
Incidentally just north of Port Elizabeth, where Humewood gc is, about an hour or so drive up towards the town of Alexandria there is some amazing coastal dunes that get as high as 300 feet (maybe more). They are certainly some of the biggest dunescape I can think of in South Africa. A colleague and I did a number of site visits, including one with Nick Faldo, back in 2006/7, and routed + staked 36 holes on some of the most natural golf terrain I have ever seen. Also the land was bounded by sea and national park so very secluded. Hopefully one day the golf courses gets built because it would be ‘wow’ in a special setting.