I really like the Franz Josef Austrian stamps, and although I am a WW classical generalist, not an expert on Austria, I'll show how I broke down the coarse print/fine print differences.... Austria 1867-72 Scott 31 15kr brown
I call this a coarse print. Note the 'rough" beard, and the fairly heavy eyebrow.
As you know, the coarse print is found 9 1/2 perf, but the fine print also can be found as perf 9 1/2, so no help there.
A big help is a postmark. Since the coarse print was issued 1867-72, while the fine print was issued 1874-80, that should often give a great clue.Austria 1876 Scott 34 2kr yellow
I'm calling this a fine print. Notice the "non-rough" beard, and the less prominent eyebrows.
Also, besides a perf of 9 1/2, the fine prints come in perf 9,10 1/2, 12, 13,and 9 X10 1/2: generally for a high CV.
Austria Scott 28 & 35 3kr green
"Rough" vs "fine": Note the '81 postmark on the "fine"Austria Scott 29 & 36 5kr rose
Note the quite marked differences in appearances between the two stamps.
BTW, can you ID the type? Austria Scott 30 & 37 10kr blue
Hope this helps.
Note: I reserve the right as a generalist to not always be correct.