I bought a FS4000US a few years ago with no film strip holders for about $50 new because the holders are difficult to find. I called up Canon in New Jersey and had to make a few phone calls, hardest part was finding the part number for the film holder, then I had to call Canon parts and they had plenty, cost me $11 plus shipping.
My tray has no numbers or anything significant markings, except 35mm Filmstrip Holder. When i called they had plenty of 35mm, slide, and APS holders
Leica M2, IIIc, Bessa R, Ricoh GXR/GXR-M
Canon 50/1.2, Jupiter 8 50/2, Elmar 50/3.5, Collapsible 50/2 Summicron, CV 21/4, CV 35/1.7, Elmar 90/4