Greetings:
I think I sent you a link with the Canons from the 2 Councils of Constantinopile 381 and 382. The Synod Letter speaks of a Council in Rome around that same time, i.e the Often debated Council of Rome in 382 that some protestant internet theologians say never existed. There is also a mention of a Tome from the Western Church. Most Catholic Scholars, save a few infected by modernist ideas, suggest this Tome is likely from Pope Damasus. Yes, there were some additions to it added by Pope Gelasius, such as a quote by Saint Augustine, but that does not mean the entire document was a 5th century work of Pope Gelasius.
http://thecatholicvoyager.blogspot.com/2012/09/the-canon-of-scripture-damasus-and.html
The Reformed Church Historian, P. Schaff has an interesting commentary on the COuncils of Constantinopile and just “What the Tome of the Western Church actually was”, he concludes it is likely from Pope Damasus and represents the Decrees of that Pope. He states there are fragments Damasus decrees which are valid, and yes, there were additions added to them by Pope Gelasius and maybe a few by an Roman priest in the 6th century, but that does not refute that 1) There was a Council in Rome in 380-382, and 2) A Decree/Tome from Pope Damasus was issued. Of course, Von Dobschutz was part of the Higher critical German movement of theology so, not trying to attack his person, he was likely a fine gentleman, but personally, I am always skeptical of higher critics, Catholic ones included.
http://www.ccel.org/ccel/schaff/npnf214.ix.viii.vi.html
I am posting from a laptop which makes my typing even slower (stiff fingers), so i am only going to say that the issue on pope Damasus (the murderer) and the Gelasian decree, is what modern scholarship has found due to increased research.
But the point is that Trent was the first infallible definition, and before that debate continued, not like that of modern revisionists favoring women ordination, but by men of antiquity was well as opponents of Luther over a matter that was considered to open to debate that Luther’s rejection of 2 Mac (TMK), was not a charge against him, but which required Rome to finalize her canon (yet that of the EOs is not exactly the same, but it not made an issue).