Not sure of the equation you use (I'm not very mathematically gifted).. but here's how I use the 1 in 60:
Firstly, determine the Initial Track Error, and correct for it. This will then have you paralleling your intended track.
Now determine the amount of distance remaining to your desired position where you wish to join your original track. If this is the remainder of distance to your destination, then so be it.
Figure the angle required to rejoin, and then add/subtrack that as well. Voila !!
eg. 100 mile leg, heading 090. After 60 miles you are 6 miles right of your track. That's 6 degrees in error, and in this case, subtracting 6 degrees from 090 = 084. Now this will parallel you to your track, and NOT get you back onto it...
Now there's 40 miles remaining to your turnpoint, and you are still 6 miles off course. I make that an extra 9 degrees adjustment, to arrive at the turnpoint. 084 - 9 = 075
Does that work for you?
PS. No slur intended on Pitts flyers Navigation technique...