It was suggested to me at the time ( and I used ) de-soldering braid that you can buy CHEAP at Dick smiths etc ( in 2 mtr lengths I think )when I did the Time Warp playfield and , although it is thick and ugly - it did work.
However I have since been told that the picture hanging wire ,that I see you are already looking at as a possibility, is a good and also neater option.
