Hanover and Hindoo prices

[Jonathon Green]

Can any racing man or woman help?

I quote from Clarence Cullen _Tales of the Ex-Tanks_ (1899-1900) 364:

"Somehow or another," went on Ex-Tank No. 27, irrelevantly and dreamily, "
I could n-o-t, not, get 'em right that winter. They may have been running
for Hogan, but they weren't running for me. When I'd dig a sleeper up, and
get it right, and lose rest waiting for the day to go down the line on it,
confidently expecting it 'ud be 30 to 1 or better, the word got out every
time, by the under-ground, or some way or another, and the skate 'ud
prance to the post with 1 to 3 on chalked in front of his name [...] Every
one that I looked over and saw worked at grey dawn and salted down as the
right goods the next time he went to the pump for long money had a Hanover
or a Hindoo price tacked to him when the slates went up.

So what is a 'Hanover' or Hindoo' price. I can see what it means: short
odds, but why? Something to do with the 'H'? No sign in OED, HDAS,
Mathews' Americanisms etc.

Jonathon Green