is there a way to convert tlg txt files (accompatied with idt files (containing line numbers etc?)) to readable unicode greek (preferrably with line numbers etc)? I mean the files that come in pairs such as TLG0208.TXT and TLG0208.IDT.
I’m not sure this will help you, but the AncientGreek spellchecker package for LibreOffice comes with a suite of macros, one of which converts Beta Code to Unicode. Could be worth a shot.
http://members.hellug.gr/sng/ancientgreekoxt/
You should also be able to view TLG files directly in Diogenes, a free program for searching and browsing TLG files.
https://community.dur.ac.uk/p.j.heslin/Software/Diogenes/index.php