Metal Strip Holders!
I not only remember metal strip holders, but the delight when we found that the first rubber ( yes there was an era of rubber between metal and plastic!) holders made great windscreen deicers!
Metal strip holders were general when I joined as a cadet in 1963, but were gone from LATCC (the old Centre, Radar and procedural, North Side Heathrow,) when I got there in 1966