In contrast to the bias illustrated in Mark Neal's results (smaller constant on the smaller cal course), mine showed the opposite bias, which is exactly what you'd expect if there's some wobble in starting and/or stopping the bike. In fact, as I still have a copy of the complete 11 page report that I sent Pete, here is page 5, containing my analysis of the "Calibration-Wobble" effect:
As for my methodology in that experiment, I'd wondered whether I might have supplemented the Jones counter readings with spoke counting (which I sometimes did when using short cal courses). It turns out that I didn't do any spoke counting; I used only the Jones counter, but tried to read it as precisely as possible. I wrote on page 2 of my report: "I always reset the counter to a multiple of 1000 counts before starting the bike... And I read the counter to as small a fraction of a count as possible (often to 1/4 of a count)."
As we know, the minimum cal course length prior to 1987 was 800 meters. Based on my 1983 experiments, I suggested it be reduced to 300 m (as Pete also suggested), partly due to the resolution of the Jones Counter, but also because, due to the theoretical Calibration-Wobble effect, constants would become increasingly inaccurate for cal courses much shorter than 300 m.