ok minor update of sorts. From what I can ascertain n12 and n13 strut tops are actually more or less the same, just that the strut tower they are fitted into has the 'reverse' bolt pattern (so on n12 the 'single' nut is toward the outside (like a 1200) and the n13 has the single nut toward the inside.).

I should have a definitive answer on their adaptability in a day or two (I swear this won't take as long as the 'chinese democracy' album)