Pat,
Most of the old classics have lost their original green shapes in the 70's, when speed became more important than quality of cut and architectural integrity. The problem doesn't lie in area to turn a mower, it has to do with cutting the cleanup pass. Sharp turns, such as a rectangular shapes, can't be accomplished with a triplex. The only way to achieve this with a triplex is to walk mow the cleanups.
These shapes haven't been lost, they are still there, they just need to reclaimed. Most expansive rough areas accross the back portions of old greens used to be green. It is easy enough to tell where these lines start and stop be probing to match soils types. Then all you have to do is strip this rough out and replace with greens height sod. Preferably grown on site with aerification plugs from existing greens, so the sod matches native turf.
DPL11