I work for a school district. Our grounds department uses John Deere E35 edgers currently. The reason they love the E35's is the drop-down curbside rear wheel for edging looooong stretches of curb. As of the last year or so, we cannot purchase certain critical repair parts for these units to keep them going. Can anyone recommend a walk-behind that will hold up to commercial (ab)use and has a drop-down curb wheel feature?