It seems anyone's guess is as good as the other's on the construction technique regarding grass establishment on the mounds next to bunkers. I'm guessing that once he got the mounds built up and shaped, he stripped off large swatches of prairie grasses, and used them sort of like sod clumps, and over time, added more soil and seed and the whole process took years to get it nice.
I have tried to remember from the first times I played at Lawsonia as a boy in late 50s early 60s, how the boxcar green was set up. I don't remember the native being that pronounced, and very well did have shorter clipped rough up on the left side hill with a bunker over there, leading down onto the large green. The two tiers were always as pronounced. I find it interesting on the old aerial that the look off the tee on 13th must not have been so 'en eschelon' as they appear today, or when I first saw them which is more like current.
The thing that really gets me is my memory of the actual small white shack clubhouse, which was more or less like a hamburger stand, with a spring on an old black wooden screen door. I remember a modest parking lot, basically the same multi tiered practice green. But the old aerial really doesn't look like there was hardly anything of a clubhouse parking lot when the aerial was taken.
One of these days when I go play there, I'm going to go early and stop at the county court house and look for their local library, and see if I can dig up any more old photos taken on the ground in the 30s-40s-50s.