Lets say that I have 3 file: `1.txt`, `2.txt` and `3.txt` which have all be gzipped. I'm aware that gzip allows multiple files to be combined using cat:

```
cat 1.gz 2.gz 3.gz > 123.gz

```

However when 123.gz is extracted it will produce the original 3 files. 

Is it possible to combine the three archives in a way that the individual files within the archive will be combined into a single file as well?