Even though I own six of Ralph’s chair backs that required the cut chair, I think his ingenious “no cut” option is certainly worth considering. (He didn’t have that available when I bought mine.) I’ve seen both in person at STAR TREK CONTINUES. The “no cut” option slides on firmly and grips the back of the chair.
Had the “no cut” option been available for the 115, I would have done that.
It’s not available for the 116 – the “slope” of the chair back is too steep.