As a follow up, thankyou to everyone for your help! MKVToolNix is fantastic, and does it all - question answered, thanks again!

Mkvtoolnix

I'm sorry, I've done a poor job explaining. The source has split the movie, intro, and credits into 3 video files, and i'd like to make them one file, before or during the re-encoding process, so that the final movie includes the intro and credits. I'm currently grabbing MKVtoolnix, to see if it can do it, but I completely missed @roawre@feddit.ch comment, so thank you for re-iterating, thanks to roawre for the original comment, and thanks to everyone for their responses, getting into this seems overwhelming and i'm so grateful to have your assistance!

Also, the files I have are ".m2ts", will mkvtoolnix support this, or will I need to encode first? MKVtoolnixs website seems to imply it only really likes .MKV files

I currently use Handbrake (I'm not much without a GUI aha) but it doesn't seem to have any options for merging / combining video files. I'm hoping to encode here, but the bluray source splits the movie into a couple of video files, and I'd like to combine them first before encoding

Been seeding this 24/7 for weeks and barely upped anything so far, community has been amazing surrounding the closure of RARBG. Lots of people trying so hard to always help this community, and I'm proud to be a part of it. TY everyone for all you do, and yarrr