Barnstormer,
If you are looking for recommendations on further mods:
My 180 has repeatedly suffered leading edge damage to the HS from off airport and rough field ops over the years, so I decided to install the Tanalian Aviation horizontal stabilizer kit on my wagon.

The STC replaces all of the skins, incorporating replaceable leading edges that are 0.040" thick as opposed to 0.020. It also bumps up the lower skin thickness to 0.025" and eliminates the spanwise seams in the skins.
It feels incredibly stout compared to the stock stabilizer.
The drawbacks are:
1. added weight - Probably 5 pounds on the tail (which is actually favorable for many wagons)
2. a large rock strike would likely transfer more energy inboard to the attachment structure and the tailcone than a stock leading edge.
Joel at Tanalian Aviation said that he has 65 of these kits flying and has never sold a replacement leading edge.