^untagged shows kind of comes with the territory, so I don't get too worked up about it. Unless they're untagged, and the accompanying text file is also a non-standard mess with un-numbered song titles, track breaks not covered in the next file, song length data next to the song, etc. Blood pressure rises, but ultimately I'm paying nothing but time and I'd have no recording if not for the tapers, so I'm thankful they shared.
I remove stuff like track numbers or timings using a search with a wildcard.
When Audacity exports labels, it give me the start and end times in decimals with a tab character between them so I search for the following string, then replace it with an empty line in Mac TextEdit
if it looks like
0.0000 (tab) 125.650 (tab)
125.650 (tab) 500.050 (tab)
500.050 ... etc etc
I search for #.# (tab) #.# (tab)
where the numberings are wildcards for any digits, and this works great.
Similarly, removing characters from a list starting with tabs and then open bracket, digits, colon, digits, close bracket will cover something that looks like (tab) [5:45].