This can be done by exiftool without scripting. To set the time stamp, you could run
exiftool -ext jpg "-DateTimeOriginal<19${Directory;m/(\d\d)(\d\d)(\d\d)/;$_=$3$1$2} 12:00:00" /path/to/mmddyy/

Then the incrementing and moving of files can be done with
exiftool -ext jpg -Directory=e:\Fixed\ -overwrite_original "-datetimeoriginal+<0:0:${filesequence;$_*=3}" /path/to/files/

The first command takes the directory, looks for 6 consecutive numbers which it assumes is the mmddyy, reorders them and applies the result to the DateTimeOriginal. Colon separators are not mandatory for this, see Exiftool FAQ #5, 3rd paragraph which starts "Having said this…". This command does require that the mmddyy part of the path is on the command line. You can't CD to the directory and use a dot as the directory name. If would also required refinement if there was another pattern of 6 consecutive digits somewhere else in the filepath.

The second command increments the time on each image. Additionally, it will move each edited file to the e:\Fixed\ directory as it updates.

In both cases, I used the -ext (-extension) option rather than a wildcard, because wildcards won't work in case you have to recurse into subdirectories (see Common Mistake #2).