I find it fascinating that the ISO standards are just named ISO and a random number (presumably an ever increasing unique number?) that can be a standard for anything from shipping containers to date formats to photographic film speeds
This is magnikficent, and I am particularly tickled that you went out and bought a corner casting. The old-school model engineering folks, when confronted by features of old castings, often approximate these not just as you have done, but also by building the parts up from smaller pieces, silver soldered together.
