L is the opposite position to A, so also an edge letter. I too learnt to type in part on a mechanical typewriter keyboard -- there was a TV kids show about jou

L is the opposite position to A, so also an edge letter. I too learnt to type in part on a mechanical typewriter keyboard -- there was a TV kids show about journalists and I wanted to mimic them I think. IME (a long time ago) you wanted to have consecutive keys on opposite hands because it took the whole hand moving to provide a good force to move the key and impact the ribbon hard enough to make a good print of the letter. But then, as you said, you would occassionally get the type arms locking up. I definitely couldn't use my pinky to type on that keyboard. TH, ER, ON, AN are the most common letter pairs [in British English]; TH is good on a QWERTY but the other pairs are not particularly well placed I think.