nzbmx406

I have a quad serial number 10 83 0146 I guess that means October 1983 renolds 531 sticker on it when I brought it new , then sold it and frame was broken where top angle tube meets the top bar .brought it back after 29 yrs and now want to tidy up the weld what it top tubes made of ? There is also a small score around the top tube , dead straight and all the way around ,anyone know whats that's about. orginal camo pad a bit stuffed does anyone make these ? Any help would be great cheers terry