Is it the case you can copy and paste the contents of the second part to the end of the first and remove the middle code, whichever part/s of the below information provided>? And what if the two starts are then identical keys? What would need to be replaced to make the combined valid and playable?
The start of the first file
{"v":"5.7.8","fr":30,
The end of the first file
,"bm":0}],"markers":[]}
The start of the second
{"v":"5.7.8","fr":30,
The end of the second file
,"bm":0}],"markers":[]}