My first Britains' 4.7! Patience on eBay paid off, though I still don't understand why the price of these toys varies so wildly. I picked this up for a few quid, yet elsewhere what appears to be the same gun is going for twenty or thirty pounds.
It did have some rust spots and chipped paint, but I treated the rust patches with some Hammerite Krust. You just paint this stuff onto the rust spots and in 15 minutes it acts chemically with the rust and becomes black and hard. These areas can then be cleaned up or painted over with a top coat - I decided to preserve the toys original state and just polished these spots up and will finish them off with some light engine oil to prevent any reoccurrence of the rust. I'm really impressed with it.
I hope to nab a second, I have several on my eBay watch list and I guess I just have to be lucky.