to Jax,
Thanks for you taking the trouble to study my post.
What follows is further explanations or where to find them.
2 Cor 1:1-2 and 2 Cor 13:11-14 seem to be to have been fabricated when the epistle was combined from three letters. Apparently, none of the intro and conclusion from the three letters were adequate for the (canonical) epistle.
For 1 Corinthians deemed interpolations, please consult
http://historical-jesus.info/co1c.html and "find" on: 1cCORINTHIANS: later additions
For 2 Corinthians deemed interpolations, please consult
http://historical-jesus.info/co2a.html and "find" on: 2aCORINTHIANS: later addition
There, I go into lot of details into explaining what I consider interpolations.
Actually. I went verse by verse for the Corinthians letters with plenty of comments:
http://historical-jesus.info/co1a.html
http://historical-jesus.info/co1b.html
http://historical-jesus.info/co1c.html
http://historical-jesus.info/co2a.html
http://historical-jesus.info/co2b.html
http://historical-jesus.info/co2c.html
This what I have for Philippians:
'aPhilippians' (written 53-56?, likely 53-54): Php4:10-4:20
'bPhilippians' (written 56, a prison letter): Php1:3-3:1a
'cPhilippians' (written 56-57): Php3:1b-4:9
See details here:
http://historical-jesus.info/phpa.html
http://historical-jesus.info/phpb.html
http://historical-jesus.info/phpc.html (I consider 3:20b as interpolation as also 1:1)
For Romans, I did not study it in depth but I did not see, reading that epistle over & over, any sign it was composed from multiple letters. However Ro 16:25-27 is obviously an interpolation.
For Galatians, 2:7-8 (except "on the contrary") is most likely an interpolation.
For 1 Thessalonians, see the top of the page
http://historical-jesus.info/hjes3xx.html for explanation on two interpolations.
Cordially, Bernard