Again About US Scott #70 And #78

Hello to everyone,
Bought old collection of US, found this stamps and cannot identify for 100%, all stamps show different shades and at least 1 - thin or thiner paper than other copies here.
Maybe someone will help where to look for details to understand how to identify this stamps for sure.
Nice day no everyone

These stamps are notoriously difficult to identify especially from posted images. I would hazard a guess that the first and last are 70's but beyond that? Age, dirt, toning, computer monitor differences all make it difficult. Physical exam helps because the paper thickness and type means a lot.

Which stamp do you believe is thin paper?

Perhaps someone that is an expert on this issue will come along soon.

Thank you for your reply,
I'm understanding about scaner-monitor issue, so I made scan for all 5 stamps in a row, thinking that maybe this can help :)
Paper that looks thin or thiner than other - last 1 with number 136a on gum side and maybe 3rd (with large tear) But as for me paper is hard so looks like more transparent
Also number on the back of stamps - 136a and 157 - what type of catalogue is it?
and this stamp in the center (3rd) - isn't it 70b ? As colour looks like steel blue as for me