Another source is the Instructions For Armourers 1912 Addendum Instructions For Care and Repair of Rifles, Magazine 303-Inch Pattern 1914. dated 1918. This reference goes into detail the procedures for maintenance and repair of the Pattern 1914. It details the differences in each manufacturer and compatibility of parts. At the end of the document, it discusses the accessories for the rifles.

Some the references that you listed have to be taken with a grain of salt. I have found errors in the M1903.com markings list. For example the Eddystone Buttplate are discussed as not marked, I have found that Eddystone stamped a small "e" on the outside of the plate where the most wear takes place and is often worn off. Additionally the Remington Buttplate trap are marked as well but you have to remove the buttplate trap from the Buttplate in order to see the small "R" stamp on the side that is not exposed when assembled into the buttplate. I suspect that unmarked parts are from very early production rifles (or Pattern 1913 rifles) were the manufacturers marking has not taken affect yet.