Inspiration for this puzzle
Here is a picture of my actual computer keyboard. I posted it here originally. https://lifehacks.stackexchange.com/questions/23760/i-like-my-computer-keyboard-but-the-letters-have-nearly-worn-off
As you would expect, letters are worn pretty much according to the use I have made of them. Also worn but not shown are I, O, H, L, and N.
Background
A typewriter-repairman receives an old model to be renovated. At first glance he recognises it to be an Adler from the 1960s. The typewriter has the ordinary English, QWERTY keyboard of the day. All key tops are in the correct position.
Then he notices something very odd. He is used to seeing wear of the keys in certain places. These are approximately as shown in the above picture.
What he sees is a very different pattern of wear. The following shows the amount of wear for each key starting with the greatest.
- A - (most wear)
- L
- K, O
- D, N, Y
- B, C, E, J, M, P, R, S, U, W
- All other letters no obvious wear
He doesn't concern himself with the space bar, shift key or punctuation keys.
Question
Can you explain this unusual pattern of wear? What was typed? Who can you expect to have owned the typewriter?
Notes
It is always difficult to estimate the difficulty of one's own puzzles. Someone may have a lightbulb moment with this but, if not, I'll add more clues one by one.
You can assume that ordinary English dictionary words were typed, separated by spaces in the usual way.
You should be able to explain all the facts I gave under Background. Nothing about the typewriter is irrelevant or arbitrary.
Please ask for any necessary clarifications before answering.