Where to start? There were as many iterations of an off-the-line drill as there were drumcorps in those days, roughly some 3000 given the timeframe. Visually the best reference I can give you is a DVD of the 1967 CYO Nationals and 1967 American Legion Nationals made in 2006 by CPM Systems. Unfortunately I can't remember where I bought it, perhaps others here can chime in with that info. That series of DVD's will give you more ideas & info then you will ever need. Drills from the Master of that era. Jimmy Costello, Vinny Ratford, Carmen Cluna, Jack Roberts, Frank Kubinak. BTW the Off-the-Line drill was perhaps the most difficult drill to pull off given the requirement of the starting line position and "turning" the horn and drum lines without suppressing the overall sound quality, something very few corps did well back then. I believe the midwestern corps had a better handle on this than we eastern folk and Mike is correct that the most impressive and difficult OTL drill is the Troopers 50yd. company front, IF IT"S DONE PERFECTLY.