Hi all.
If your looking to add a spot of rust to your model, then a product from
WWW.RCTANKS.DE in Germany could be just the job. As the web site suggest its meant for tanks but will give real rust on almost any surface. It comes in two bottles A is an iron primer that you brush on where you want the rust, this is done twice after a 10 minute wait, then 24 hours later brush over with B, an oxidant, and then wait and rust will form over a period of hours. It is very effective and you soon get the hang of just how much rust you want. Cost is 18.99 Euros plus postage, and delivery is quick. Just an idea, might be of help to some.
Richard. :)