Bongo Fury

Whilst fitting towbar electrics needed to pull off rear door seal, found nasty rusty bits where body is pressed together in each lower corner, did the grinding and treating, looks OK now. Rubber has obviously held the moisture and caused the problem, worth pulling them off and having a look?

Can anyone tell me why there is so much soil (probaly started as dust) in every crevice and behind every panel I remove? Bad feeling the previous (Japanese) owner was in to off roading and coffee pitching.

i think you will find, that there will be rust in most places where metal is joined together, it is known as dissimilar corrosion, it is caused by the conductive properties of metal, and it helps to creat a "hotspot" for rust to form, (it can be the same type of metal, doesnt have to be 2 different types)
1 prevention is to use a jointing compound, if its too late which it proabaly will be by now as most Bongos are 10+years old. You can use a rust converter that turns it back to metal, screwfix sells the converter stuff.

but good old sandpaper and undercoat is just as effective, the converter should get to most of the rust that is deeper than you can see. it also protects it very well once it has gone off.