I have recorded myself reading 2 John and 3 John in Greek using the Koine Era Pronunciation (aka Reconstructed Koine) from the Greek New Testament Produced by Tyndale House. I previously recorded myself reading 1 John in Greek using Koine Era Pronunciation. You can find that recording here.
Feel free to download and share the files, but please cite me if you share it online (a link to my site is sufficient).
2 John – v1 – AAC (M4A) Format
2 John – v1 – MP3 Format
3 John – v1 – AAC (M4A) Format
3 John – v1 – MP3 Format
Jongkind, D., Williams, P., Head, P. and James, P., 2017. The Greek New Testament, Produced at Tyndale House, Cambridge. Wheaton, ILL: Crossway.