Start with Q86QH9, Q86QI0, Q05831. Enjoy.
Yeah "we" were waiting on you. Finally you produced something that might bring your sequence "homologs such as the protamines may well have served some entirely different function before doing what histones do now. A minor change to that homolog, and presto - histones" out of the fiction category.
Now you mention protamines having a minor change and presto a histone.
The accession numbers you gave are not protamines but contain protamine-like sequences and are of histone domains. So what you evidently are saying is that the protamine with a minor change became .... well let's look at the sequences.
1 mpspsrksrs rsrsrskspk rspakkarkt pkkpraaggv kkpstlsmiv aaitamknrk
61 gssvqairky ilannkgint shlgsamkla fakglksgvl vrpktsagas gatgsfrvgk
121 apaspkkakk akspkkkssk nksnnakakk sprkkaavkk stkskakkpk spkkkaakkt
181 arkspkkkar kspkkkaakk skk
akakksprkk aavkkstksk akkpkspkkk aakktarksp kkkarkspkk kaakkskk Q05831(Protamine-like protein PHI-3)
1 aggvkkpttl smivaaitam knrkgssvqa irkyilannk gintshlgsa mklafakglk
61 sgvlvrlkts agasgatgsf rvgkapaspk kakkakspkk ksskksknks nnakakkspk
121 kkadsn
akakkspkkk adsn Q86QI0(Protamine-like OS3)
1 mpspsrksrs rsrsrskspk rspakkarkt pkkpraagga kkpttlsmiv aaitamknrk
61 gssvqairky ilannkgint shlgsamkla fakglksgvl vrpktsagas gatgsfrvgk
121 apaspkkakk akspkkkssk ksknksnnak akkspkkkad sngiryqayr yrrprggary
181 pfryqayryr rprggpgtqf al
1 akakkspkkk adsngiryqa yryrrprgga rypfryqayr yrrprggpgt qfal Q86QH9(Protamine-like OS3)
Those small parts are protamine-like. The rest of the sequence for each is histone-like. So essentially what you are saying is that the small part with a minor change, "presto", becomes the whole thing. Nope, that is still in the category of fiction. A minor change is considered somewhat less than adding 100% of something.