Defile or Define rule lines?
You draw them as graphic lines. You set them to float in front of text rather than being in-line with text. (The whole header layer is behind your body text.)

Same with the text box. A text box is a graphical element in a separate layer. I also have the text box (drawn inside the header) float rather than wrap or being in-line with text.

I group the rule lines together so they can be moved as one unit.

You will want, I expect, fixed spacing for your line numbers, to simulate the line numbering on a typewriter. (This is almost as good as August having 31 days to flatter Caesar or the QWERTY keyboard arrangement designed to slow down typing!)

Hope this helps.