Beyond that, its likely is a permanent mark against the air-frame which makes it basically impossible to resell. Including the fact it might have added an additional inspection interval at the strut attachment points. Might even have ended up as an experimental cert due to not conforming to the type any longer.
Also, i'm not so sure there is a lot of formal engineering going into a mod like this on a GA plane. More likely someone has a rough set of parameters for air-frame shear/etc stress and a quick calculation said that the additional stress at 120MPH and landing shock was a small percentage of the total.