They did ask Noddy Holder, but he didn't want to leave Slade back then, even though Slade were in the doldrums in early 1980, their comeback via their last minute appearance at Reading was still a few months away.
https://myvintagerock.com/2014/08/15/slade-become-heavy-metal-heroes-at-the-reading-festival-24th-august-1980/In 1979/80, Slade, the band that had sold out Wembley Arena on four consecutive nights in 1973, was back to playing working men clubs up North.
But if you look at what Brian Johnson did with Geordie, then the Young brothers did not stray too far in their search.
Gary Holton was approached too, he sure had that Bon Scott street urchin swagger, perhaps a bit too operatic for the Aussies, he eventually turned to (actually successful) acting, but he died in 1985 as a habitual heroin user with a blood alcohol level of 199 mg and a morphine level of 0,8 mg per liter (0,5 mg per liter is considered invariably fatal):
He was a riot on stage and an admitted inspiration to a young Irish roots kid from North London who’d later go by the name of Johnny Rotten.
And Dan McCafferty of Nazareth was on the list as well (he also preferred to hang on to his buddies) - you can tell by all the singers that AC/DC approached that they had a pretty good idea of what they were looking for, it’s that one type of high-pitched gravelly shouter with dirt on his vocal cords. Basically someone who sings like an overdriven guitar from the gutter.
I’m surprised they didn’t hit on Michael Des Barres though!