Thanks for keeping us updated on the Stuart John. Good to see the tracks back on the machine!
There are some good youtube vids on the use of molasses for de-rusting. I have cleaned up some parts with this mixture as well. In my opinion it works really good for cast parts, but had some trouble with a very thin piece of rusted sheet metal....there wasn't much left after a few weeks in the molasses bath
I think I have seen some pics on HMVF, where someone dropped a complete cannon in the stuff.
Alex