Possible Clues:

• Pure oxygen smuggled in using barrels of blood?
• Pedigree
• Pedigree racehorse
• Sweeping floor around back of larder having quality in stock
• Pedigree during race almost turned outside ring
• A horse of pure lineage
• Scrupulous local capital report is something worth backing of course
• Of outstanding quality
• Meticulous with money, wanting a horse
• Racehorse, however unkempt, initially black, then scarlet