The decision to restore an item or not is a very personal one. Sometimes an item is best left alone, especially if it has a history. Sometimes however the decision to restore something can be the right one from the point of view of perservation. If something has original paint then my advice would be to leave it alone.
Rust Oxide on original painted surfaces:
There is a product on the market called "evapo-rust" which is a
ph neutral dip that attacks the rust oxide without attacking the
paint. This product will remove a lot of rust oxide from the
painted areas to improve the look of the item. If an item with
original paint is likely to rust again after treatment, then I would
recommend a light evenly applied coat of matt laquer which will
protect the item for many years to come. Never leave an item in
soak for more than 45 minutes without checking the item.
Dipping for too long will result in the paint peeling. Short regular
dips are best, dip for 40 mins then brush off any residue with a soft bristly brush then leave for a couple hours before re-dipping until you are happy with the end result.
Cleaning steel items:
Wire brushes & scotch abrasive pads are fine to use on rusted or corroded items but you must be very careful. It is very easy to get carried away & loose original Luftwaffe inspectors stamps & original factory "machine milling" marks which are always nice to see & should always be preserved where possible. Blasting is always an option on heavily pitted items but Sd2 drogues should never be blasted as the steel case & wings are just to thin to stand such a treatment. Plastic media such as glass beads is always better than sand or grit.
I sometimes paint the inside of bomb casings with dinitrol, this is a brown waxy liquid that dries to a tacky waxy finish. It is very good for peservation in areas that are not normally seen. When applying this, you can use white spirit to thin it down a bit & using this product in a warm environment always helps. You can also soak the tin in a bucket of hot water to warm the liquid up which makes it easier to apply.
All most all german bombs were originally primed with a red oxide as an undercoat primer, therefore I normally use this product in a spray form on all my restorations prior to re-painting. I personally never use any gloss paint, I always have my paint mixed up in matt at car paint specialist. If using red oxide test your chosen paint in a small area first as some paints can attack the red oxide undercoat resulting in the item having to be completely stripped back to bare metal again.
World War Two - Air Dropped Ordnance
German Sc50 case
German Sd50 fins
German Sd50 case
German AB-70-4 Sd1Container (Abwurfbehalter)
First used in 1943 it could hold 50 Sd1 Splitterbomben