Actually, I scoured the web and came to the same conclusion re. Mr Covel.
And also found the Turtle rules for free. Have you followed them since your discovery?
After reading through I got stuck on their entry rules:-
System 1 breakout entry signals would be ignored if the last breakout would have
resulted in a winning trade. NOTE: For the purposes of this test, the last breakout was
considered the last breakout in the particular commodity irrespective of whether or not
that particular breakout was actually taken, or was skipped because of this rule. This
breakout would be considered a losing breakout if the price subsequent to the date of
the breakout moved 2N against the position before a profitable 10-day exit occurred.
Does that make any sense to you?
Anyway, thanks for the heads-up.