Post a pix of it. and by the way
I also have a small flock and I like to repurpose things as well . I was recycling before it became popular.
here is a pix for my 8 girls, mostly banties.
Let me ask the correct number of birds. Is it a total of 40 , or also 30 add to the 40 which is 70. Lets work with 40. You will need a coop about 12 x 12 at least to house 40 and it may be tight, and crowded. If you make it 7 feet tall , then you will have enough height to walk in...