I would try and feed 5 pounds of beetpulp, 3 pounds of oats, 1 pound of stabilized rice bran and 1 pound of Calf-mana twice a day and Bermuda grass hay.
Work him down to this ration, should take a week as you add a pound of each the pulp and the oats take 2 of grain away, once you reach the ration of pulp and oats cut out the grain. You will need to weigh him twice a week at the same time to see how much he is gaining. If you can keep him to about 1 pound a day for 30 days that puts at 1280 early December, start increasing his feed and taking away the pulp and oats, I would take about 2 weeks to bring him back on 2 pounds beet pulp, 1 pound oats 6 pounds feed and keep him on the stabilized rice bran and calf-mana.(change the rations depending on his gain as you go) if he gains between 2-2.5 pounds a day it puts you around 1380, He can lose those 30 pounds on trip there. (3.5 gallons of water) Puts you within 3% of his weight for weigh back.
When you say he is 1250 is that full or empty? If it is full get an empty weight on him.
Do you have a weigh back and what is the percentage?