Interesting construction

When Mr. Hummel built this house in 1945 he did his best to create some sort of insulated wall, mostly using trapped air space. The wall is different from the sunroom in this part of the house. The layers on the wall, from the inside are:

Gypsum wallboard

Structure, of 2x4s laid sideways

A 1/2" layer of homosote
Structure, of 2x4s laid sideways

A 1/2" layer of homosote

A layer of black building paper

3/4" thick tongue & groove planks

Another layer of black building paper

Homosote

Shingles

I will say the contractors are scratching their heads a lot, and speculating about what they'll find next!