sorry for the delay, I have been experimenting.

The link you gave for Freedos doesnt seem to work - File does not exist. But I managed to find a copy of 128mbdos.img.

I used your dd instructions (with changes for shifted letters) on an empty 4Gb memory stick. This created a small FAT16 partition on the memory stick.

I then partitioned the remaining stick to FAT32 with partitions (gparted) for each flavour O/S.

That did not work.

I did the same with a single FAT32 partition (and the flavours in directories) with no better success.

At the time I was discouraged, with other things to do, so I didnt go further.

You are going to ask exactly what happened, but it was something like syntax error, and I didnt make a note. (sorry)

I am now going to repeat the experiment and I will report the exact result.

Thx for your help so far.