When the climactic race begins, only half of the horses announced (Gringo, Wild Bill, Shrapnel, Gallant Lad, Golden Fleece, Elsie Lee, Avalanche, Hold Away) match the names seen earlier on the odds board (Golden Fleece, Money Maker, Shrapnel, Blue Boy, Court Jester, Gallant Lad, Avalanche, Pico).
When Charlie and Lee examine the note addressed to George Chester, Charlie says it has a watermark. The camera shows a close up of embossed paper, presumably because it's easier to see.