That Wylex CU in all it's different configurations was revolutionary when they first hit the market in the early 50's!!
I'd like to see what happens to the frame when tested with this 960'C test wire, because i've tried to burn this treated and matured hardwood frame in the past.... Unless this wood was in constant contact with the red hot burning embers on the fire, there was no chance, and even then was reluctant to continue burning, preferring to glow and carbonise than to burst into flames!!!