Feeling lazy, I'm tempted to put the jet-wash on it, but is this the most sensible/sufficient thing to do?
I am intending to paint the chassis (surface rust only, I think) with Galvafroid, which should go straight onto surface rust, and, judging by our garage roof trim over the winter, works really well.
Failing that, it's back to 'ordeal by Waxoyl'...
Regards,
Simonm.