Hi Clive,
Yes, the large-cap figures in the article are total returns and are based (if I recall correctly) on the S&P 500 rather than the Dow. When I wrote the article we were in the midst of a bull market which started circa 1994.
The S&P 500's P/E, until that time, was close to the historical average P/E (after 1994, the P/E went up significantly). So from a historical perspective, ending in 1994 seemed to provide a good approximation of the true returns/risks. Note that adding the years 1995 through 2000 (the article was written in 2001) to the analysis (i.e. [1926 to 2000]), skewed the returns upwards by over 1% per year for the ENTIRE period.
Given the freefall in markets over the past year, I'm not sure what the results from 1926 to 2008 would be, but I'm sure it would be more in line with the true values than it was back in the late 90s -- as your analysis of the Dow from 1928 to 2008 appears to show.
A simple subtraction showed that real returns were about 6% (assuming a historical 4% inflation rate) which is different from the Gummy calculator results (however without having yet looked at the calculator, my guess is that the calculator's results are more accurate since I just used simple averages).
Thanks for the calculator links, I'll have to play around with them.