That's a great idea! I made something once for the same purpose, with a plane blade held vertically, like a guillotine, but instead of a head you passed the veneers under it, setting the thickness with feeler gauges. As a bonus, you could set it at an angle which was useful for doing mosaic rosettes, thicknessing each column of the mosaic at a slight angle so each square fit next to each other in an angle. (I hope I'm being clear here, as I don't have pictures and I've since cannibalized the guillotine for other things, although I can't remember what the other things were...)
What I want to know however is, what's going on in the last picture, why is that plane all taped up? Were you doing a binding job on it?
Thanks for sharing, I'm sure I'll find a use for something like that.