I came home from an auction with a box of 18x24mm film sheaths that fit inside plate holders. Since I have no use for them... PM me if they might be useful for you. This is a give away, maybe a trade if you're feeling generous and have something suitable, no charge but shipping - if anyone wants them that is. They could use a little clean up but they are in pretty good shape.
I also got two of the thick rim 9x12 plate holders. Again, a PM if you want them. I can do better than "thick rim" in terms of description.
Gotta love those $1 box lots!