I had a frameset with similar visible damage awhile back and the head tube angle measured with 'spec'. I dont know what the original angle was so I looked up what it might be by comparing various geometry table and what I measured was close enough not to bother tinkering with. Steel is unique in that it springs back a touch after an impact which expains why you'll see damage without a compromise in head tube angle.

Another way to check is to measure the wheelbase and chain stay lengths. A typical road race wheel base may bee 1005mm with chainstays of 400mm which means the distance from the BB center to fork ends would be 605mm.

go through a bunch of old frame geometry charts and calculate average dimensions of what similar frame sizes to your have and measure yours in comparison.