I didn't want to spend more bike cables because I can use them on bikes

With first one I managed to cut one of shorter sides + half of long side, with second 5 cm, with third 10 cm, then it was enough for me

With handbrake cable wires it went faster and looks like one cable can be enough for 2-4 screens, depending on luck

To hold wire I used two pieces of wood.
Two ppls which I asked for advise told me that these rubber strips must be bought new when replacing screen anyway

If principle of quarterglasses on C3 is the same as on B3, then it will be pain in arse to cut these two out. Without proper advice I wasn't able to properly remove two pieces of steel that is between bodyshell and quarters.