You are probably right Tippy, supplies have come a long way and so has the quality, I think in the days of old they used what ever they could get their hands on so a lot of the fabric as also used before being put into a quilt, nothing was wasted.
I have seen your work and it is great.
I don't always press to the dark either, sometimes if I was to then they would be going the same direction as other seams ( I guess an arguement for pressing open) I have not had anything show through, depends onn he quaity of facric that you use as well. I vary it to suit what I am doing. the stack and wack that I am still working on especially the little one I am happy that I pressed open. other things like the black and red that I am working on now, just making sure that they are on opposites.