I whole-heartedly agree Mike - credit where credit is due! I have done a bit of reading-up on Mr Vanspeybroek since seeing your post, and he sounds like a very interesting and capable guy!
In one thread on Sword Forum International from 2002 he talks about the use of vinegar on it's own to form a rust-resisting layer and the possibility of using it alongside some other chemicals: no doubt this was the beginning of the full-blown formula given above by Dllandry.
Great stuff.
Regards,
Neil