Frame Stiffeners??

[marty in Ohio]

Here's one for you guys. My '30 Town Sedan was restored about 45 years ago. It has half inch bars welded to the frame by the front axle and ending by the rear end. The bars are held below the frame by angle iron about 3 inches long welded vertically between the beginning and end of the bars. In the middle of the bars,between the angle iron, are turnbuckles on each side. It appears that you could stiffen the frame by turning the turnbuckles. I am the fourth owner and the man I bought the car from, twenty years ago, said the original owner drove the "A" in the oil fields in West Virgina. Could these have been installed to fortify the frame?
The frame looks very sound to me and I'm considering removing these turnbuckles. They don't hurt anything but they make it hard to install an exhaust system and it's close quarters on the left side by the battery.
Anybody out there ever heard of this?