This is very interesting, do you have a source? In eats, shoots and leaves I recall the claim being made that apostrophes can be used for plurality with borrow

This is very interesting, do you have a source? In eats, shoots and leaves I recall the claim being made that apostrophes can be used for plurality with borrowed words. A particular example would thus be the "potato". Therefore, a so-called grocer's apostrophe to pluralise potato would be ok, while to pluralise turnip it would not. Similarly it was considered appropriate for pluralising numbers and days of the week. "There are fifty-two Wednesday's in a normal year." However, if the contraction argument were correct then "Tomes Pen" -> "Tom's Pen" could also allow "Potatoes" -> "Potato's"