According to the 1 lb. bag of DQ Cure #1, you use 24 lbs. of curing salt to 100 gallons of water for a curing pickle. This would be the maximum amount you'd use.
Reduce that by 100 to 1 gallon, it would be .24 of a lb. to 1 gallon of water, or approx. 4 ounces of cure #!.
I use approx. 1 tablespoon to 1 gallon of water. A level tablespoon is .8 of an ounce. A rounded tablespoon is approx. 1 ounce, or ¼ the maximum allowed. And, I find this sufficient to pickle any pork or beef or poultry I need to do. I will allow more time for it to cure, just from my dad's instruction on how long to let it cure; 2-3 days for poultry, 7 - 10 days for half-butts (buckboard) or bellies, 2 weeks for picnics once pumped, 3-4 weeks for whole hams once pumped. I've never tried it with less times, simply because the cost of the product is too valuable on my limited income and unlimited (so it seems, lol!) medical bills. But, it produces a nicely cured product without the need to soak or freshen it to get rid of unnecessary salt (and I've limited the amount of salt I add also).
As for the amount of brine, your proportion of curing salt to water is the important ratio, and just use whatever amount of brine necessary to cover the product. You can pickle 1 ham in 1 gallon of water/curing salt or 100 gallons of water/curing salt, it doesn't matter, as long as it's proportioned correctly per gallon. Of course, you add more ingredients in salts and sugars, etc. to enhance the bouquet of flavors in your pickle.
Again, my dad's theory was that a mild curing brine for a longer period of time made the product more tender and flavorful instead of a shorter time, more concentrated cure. He sold hundreds of thousands of product over 45 years in business, and his customers readily agreed!