I first started noticing commercial mowing and how it was done in about 1972. I bought a old Gravely (actually 3 old gravelys that became 13 but that's another story) The place I bought parts also sold and serviced Locke. in the early spring there were probably 50 of them in there for service and blade grinding. It was unheard of for a Pro to use a rotary mower. I am sure improvements in rotary, speed, cost caused the changeover but it would be interesting to here from someone who was there as it happened.<p>Frank