VOLUME.LAB.ASCII files have been made with:
$ iconv -c -f EBCDIC-US VOLUME.LAB | strings > VOLUME.LAB.ASCII

2.4M images can't be mounted on Linux with the vfat filesystem driver.
mtools since version 4.0.28 supports 3174 2.4M images. Use like so:
$ mdir -i C6_3_Control.3174\|data_map=1s,zero31s,28s,skip1s :: -a