Measure the width of the paper, and then measure the distance between the punched holes.  It helps to make a scale with a strip of paper, which can be placed across the width of the roll and then moved to where new channels appear.  After enough channels have been marked on the strip the holes-per-inch can be determined.

The most common music rolls in North America are 11.25 inches wide and contain popular songs for the player piano.  The spool diameter is small, circa 3/4-inch (2 cm), and only one song per roll.  See "9-per-inch" table ("88-note"), or "6-per-inch" table ("65-note").

Music rolls made by the Tel-Electric Co., of Pittsfield, Massachusetts, were enclosed in a brass cylinder containing a brass note sheet (some later production was of stiff paper).  The "Tel-Electric" or "Telelectric" 65-note rolls were enclosed in a cylinder 5-1/8 inch long, and the "Telektra" 88-note rolls were in a cylinder 7 inches long.

Music rolls which play on orchestrions and nickelodeons usually are on larger diameter tubes, with five to ten or more songs in the roll.  (But sometimes one finds a single song removed from a 10-tune roll and mounted on a small spool for a Pianola!)

The spool is usually a tube of cardboard, occasionally with short wood plugs at the end.  Early flanges are wood turnings; by the 1920s flanges were stamped metal or molded Bakelite.  Most wooden flanges also have a metal pin inserted, circa  .188-inch (.5 cm) diameter.  Otherwise the flange has a concave cone to receive the supporting chucks.
 
 

(Note: I question the word 'recorded'. I have never come across any rolls that were not 'drawing-board' arranged, and the term 'played by' never  appears on the label, only 'arranged by...' or 'transcribed for...' above the artist's name, as far as I know.  Many rolls do not even give the arranger's name, and if they do, it is usually a staff person like Samuel P. Warren. The most famous 'Name' artist who appears, Engelbert Humperdinck, is credited: "Composed for the Aeolian Pipe Organ by...".  R.Z.V.)
 
 

Wurlitzer 8.15 holes/inch nickelodeon & band organ rolls

	"Wurlitzer 8.15/inch" nickelodeon & band organ rolls [draft, verification needed]
paper:	width varies with organ style
holes:	0.073 inch (1.85 mm), round
spool & flanges:	2.25 inches outside diam., no flanges
produced by:	Wurlitzer
label, 1st line:
label, 2nd line:
label, bottom:
music source:	Early rolls mostly arranged by Wurlitzer; later rolls adapted from QRS piano roll arrangements or are contract arrangements by J. Lawrence Cook.  See also http://wurlitzer-rolls.com/
tracker bar:	single row tracker bar; percussion holes often offset
comments:	The channel spacing is 0.1227", or 8.15 holes per inch.  This spacing used for almost all 5-tune and 10-tune Wurlitzer band organ and orchestrion rolls.

 

The tracker bar for the RS (Concert Organ) roll may have 97 or 98 holes.  The additional hole (#1, "sforzando") was apparently intended to augment the swell shutter controls.

Wurlitzer also provided players for their theater organs:  the Style B player used 88-note home player piano rolls, and the Style C player played both 88-note pianos rolls and the Concert Organ roll on the same player.  The Style B was usually a duplex roll player so the busy organist could switch from "Love Music" to "Chase Music" in a hurry.