GUEST,Adam1989.
In answer to your question, the skin bit of a banjo is a replaceable item which could be purchased independently of the instrument. Any identification marks belonging to the banjo will be on the actual wooden parts, whether that be a mark stamped in the wood, or a plate attached to it.
A quick web search found this page - somewhere about half way down he describes things attached to a banjo "non-descript cheap japanese tailpiece and a rather worn Rogers vellum."
This suggests to me that "Rogers" were vellum manufacturers and "Standard" was the thickness or grade of vellum and the stamp was on the "wrong" side of the skin and not intended to be seen.
A slightly different search found this page which mentions "The Art of Bookbinding. A Lecture Delivered by Frederick Rogers, President of the Vellum Binders Trade Society. Possibly a coincidence, but possibly not.

If you want to identify the manufacturer of the banjo, you will need to look for markings elsewhere.

Bo - the whole point of this and similar threads is that the instruments under discussion ARE banjos. They are not derived from Chinese bowed instruments or the Kora which, although it has a skin over its sound box, is closer to a harp than a banjo.
The instruments were by and large designed by manufacturers who were already building "standard" banjos, using the same sort of banjo bodies (sometimes made in a different size) but adding a neck with a different number or arrangement of strings.
In my book (and the manufacturers catalogues) that makes them some form of banjo.

Nobody is trying to claim that all instruments with a sound box covered with a skin are some form of banjo. What we are discussing is a family of instruments with a reasonably well documented history since it became popular in America and then moved across the Atlantic to Britain.

Quack!
Geoff the Duck.