Hi Ki,
At one time I was given a bunch of 1" reels held together with 6 screws, which I didn't need. At least for these (I think they were BASF), the three hole center plastic lined up fine with three of the holes and the three "empty" ones didn't look that bad and it worked great.
You probably have already tried it, but thought I'd mention it just in case.
I've been thinking of trying something like that to solve my need for a 12" take-up for my Lyrec. Good luck.
Brian