I am a collector from Finland. I started collecting stamps in my child hood and have collected stamps for many decades (but I am not anywhere close to retiring). I collect world wide stamps and in that sense I am not a specialist of anything. However, if I can tell them apart, I keep every variant of the stamps I can come up with (without spending a fortune, which makes me a bottom feeder). I have 50,000-100,000 stamps in my collection from all over the world. I have many world wide catalogue sets (but all of them older editions) and specialized catalogues from many countries (many of them out of date). Old catalogues are cheaper to source and the information in them is mostly valid (and new stamps are difficult to come by, which means a decade old catalogue serves me almost as well as a new one) excluding the prices, which I am not too much interested in.
I have been lately helping a retired gentleman in selling stamps on second hand market places (common way of selling odd items in Finland). Recently I have been helping with US stamps. I have 2016 Scott US specialized catalogue.
With the first design of US postage dues. I think I can safely exclude the possibility of 1879 Special printing, which leaves me 3 different issues of these stamps (1879, 1884 and 1891 or stamp numbers J1-J7 and J15-J28). I find Scott specialized useless in explaining how to tell them apart (shades are troublesome without comparison and fading and discoloring and similar make it even more difficult).
I have also visited the excellent stamp site www.stampsmarter.org.
I have used it earlier to be able to spot the differences between two versions of 2544b (3$ Space shuttle). The only place where I have found that information. I was looking that site for help, but unfortunately with my limited knowledge I was not able to use the information there to tell the 3 issues of the first postage dues of USA.
So, now I wonder if I could get help here. How should I go forward with this to get best help from this forum and to make the helping for this community members as easy as possible?
This is an example of the stamps I am talking about. Apologies for bad scann (left side has been trimmed off).