Been looking at vids for the NF3, and noticed J Hayes refers to it have a "steel bridge", which I assume means there's steel components as per the 305, DC3 and Brent Mason (others?).
Looking at pics of the the Nf3, 305 and DC3, they've definitely got a brass block (sorry to disappoint you swede71) so what exactly is steel? The saddles? The bridge body (and trem screws)?
Anyone got one any of these models and a magnet handy to check?