Sometimes I think there's no easy substitute for blood and sweat. Still, I sympathize with all those looking for a solution. I might consider replacing the bolt with a trailer ball, and adding the appropriate coupler hitch to the pipe. I think this would allow for greater freedom of movement for the pushmower....let it follow the ground a little easier, rather than being forced around by the bigger mower.
And along those lines, I would replace those plastic wheels with pneumatic tire/wheel assemblies, complete with sealed bearings. If you add an additional attachment point to the pushmower, you might also get away with casters, rather than fixed wheels.
The oiling issue may be a problem sure enough. Find an old, garage sale Lawn-Boy 2 cycle and try that instead
