open plugin file StackModifier.cs then seach for this line {"horse.saddle", 1},

Underneath that add these 2 lines 
{"horse.saddle.single", 1},
{"horse.saddle.double", 1},

then search within the file for rustige_egg and underneath these entries 
{"rustige_egg_a", 1},
{"rustige_egg_b", 1},
{"rustige_egg_c", 1},
{"rustige_egg_d", 1},
{"rustige_egg_e", 1},

Add the following {"rustige_egg_f", 1},

SAVE and o.load Stackmodifier all fixed

The plugin was designed & coded with debug code to notify me when FacePunch adds new game items to update the default coded list.
Also, the order doesn't matter, as far as where you insert them into the dictionary. :)

Merged post

I'm still working on this wipes update, adding chat/console commands still