I'm not sure about the original film but the slide positives were most likely Kodachrome (Kodak). Almost all of the ones I've been able to identify are either Kodachrome or Ektachrome (both Kodak) but Kodachrome holds up much better over time. Ektachrome slides usually have fading issues and end up with a red tint to them. I do both raw scans and color corrected but I'm usually posting the raw scans here unless they are very bad.