Uh... if it's not interlaced nor telecined and there aren't any interlacing issues (combing/blending) but you still think there's something "weird", it might be because of dups. I would say to run TDecimate and let the filter automatically guess whether a frame is a dup or not, btw I don't actually know how accurate will it be, considering it's an old material...
Besides, you mentioned the Blu-ray standard; are you actually trying to make a Blu-ray? Because although Blu-ray discs are almost all progressive, they could be interlaced as well, in fact old discs used to be like that.
Anyway, upload a sample so that we can see what's that about and we can make a script for you.
