cock on closing is not easy for me, it need allways a working brain to do it and I still believe its like right - handed / left-handed.

for me cock on opening is like being right -handed and driving on the right so maybe the reason the british with the lee enfield had the cock on closing rifle with the longest service life.
having such actions and use it together with the common cock on opening actions helps you against the common brain dead now so widespread.

dont have a Lee Speed only knowing the military rifle the action I like most in the end is the swedish Mauser.

the M 65 and M 68 were the peak of the S&L evolution and like the Mannlicher Schönauer they came to an final end between 1968 and 1970 because the quality and the craftsmanship became unaffordable than.

dont had a M 54 in my hands till know I am sure this rifles had the same peace time quality like the later models.