If I were you, I wouldn't be in such a hurry to table a such a laughable question for discussion to the present honorable forum. I would direct my attention to the first fallen in my hands dictionary in order to satisfy my intrusive studiousness.
If you have done this you would surely have read the following very simple explanation.
selfsame (adj) = being one and not another or others, not different in nature or identify
selfsame = same = identical
same (adj) = being the very one, identical, similar in kind, quality, quantity or degree, conforming in every details, being the one previously mentioned or indicated.
The expression same and the same one are sometimes used in place of pronouns such as "it" or "one", as in
"When you have filled out the form, please remit same to this office."
As this example suggests, that usage is associated chiefly with business and legal language, and some critics have suggested that it should be reserved for such context. But though the usage often does sound stilted, it occurs with some frequency in informal writing, particularly in the phrase "lack of same" , as in
"It is a question of money, or lack of same."
I know, to save labor, you prefer to ask to read but you have to know, work give pleasure not be parasite on.