Working width of mine is an inch (there is a maybe 3/16" flange on the inside about 3/16" "tall" to keep stock from rubbing up against the side of the roller housing, so overall length is 1 3/16").
Diameter of each roller is 1.24" (all three measure the same), center to center of the two fixed position is 1.625". These are not quite true vertical to the base, did not measure exactly looks to be maybe 15 to 20 degrees towards the adjustable roller. It did not look as canted as the one you posted a pic of...not sure how vital that is...
There is a 1/8" half round groove cut at .291" in from the inner face of the flange (don't know if this is common to all or if this is a common dimension, there is room to go a bit wider and a bit deeper IMO though a small width flat may then want to roll some, ?).
All rollers have a pretty deep knurl across the entire face width, the first couple of items through it was noticeable but then lessened considerably (not sure in feet how much I have put through, not a huge amount though). I am guessing the starting diameter is supposed to be 1.25" as the main dimensions seemed to be standard/imperial numbers.
Each roller has a grease nipple on center, outboard end. Each roller looks to be held in place with a "C" clip.