Finding a good one, sorry any one, is difficult enough. I doubt that SE/Non-SE is all that important as far as value/desirability is concerned, so-say 'rarity' notwithstanding; service-history, providence and condition is everything really (don't say mileage, my 'Olive' is paranoid about that!)
Would you buy a "rare" non-SE with zero service history over an SE with all the paperwork? I wouldn't.
Anyway, personally I think the more SE bits you've got the better, as an SE or added later.
David