Both very good points there; always a good idea to test them both on scrap for a reaction before committing to the finished piece
A bit more research led me to the use of BS697 'Royal Navy Light Admiralty Grey' as touch up paint for a Racal RA17, which looks a lot like I originally had in mind. I'll pop a link in here just in case it is of use to anyone else looking for similar, they have a good selection of BS381C colours that might be useful for anyone doing restoration
https://www.yourspraypaints.com/prod...t-1k-2k-400ml/