Mine is a single file 960 x 540 about 1 Gig. If your file(s) are better quality, have you heard of LosslessCut? It is a great little no frills program that does One thing, it joins files together and it is really quick. As long as the Two, or more, files are formatted the same this program can join files really quickly. A situation like yours is perfect for this program or if you have a bunch of clips that you want to stitch together, the program works great. One note, Before you join the files make sure that they are going to be joined in the correct order. Sometimes it willl default to ABC-123 A and ABC-123 B and it will set up the join as B first and A second but other than that little hitch it has always worked great for me. You can get it in many places but I suggest here,
https://github.com/mifi/lossless-cut Click the little green button that says code then download zip. If that doesn't suit you and you want my vid, let me know and I'll ul it. My ul is very slow but I'll get it uploaded for you if you want it. Cheers. The rapidgator version, linked from
https://www.japanese-bukkake.net/?s=kv-178 is much higher quality than mine, about 3G in total but that is in 2 Pieces. With the Lossless cut you could remedy that issue but if you're after higher resolution that would be the way to go. I suspect that this is what you already have so I would say just stick dem ol pieces together and ta-da you have a full vid. Oh, one other little issue with the software. it creates teh joined file in the same directory as the original files so don't forget to delete the originals after you've confirmed that the file has joined correctly . It will append the filename with ...merged.