Fuel oil is approximately 140,000 BTU per gallon. A good boiler will deliver maybe 85% to the house (don't quote me on that, I'm no pro). So 119,000 BTU per gallon. So 2800 gallons in a year is 333 million BTU.
Anthracite coal number I have read are 22 MBTU to 25 MBTU per ton. Call it 22 to be conservative, and 70% efficiency in your setup, so 15 or 16 MBTU delivered per ton burned.
25 cords of GOOD wood (i.e. dense wood) might be 62,000 pounds, 8000 BTU per pound gives maybe 500 million BTU, but adjust that by the same 70% efficiency and you have 350 MBTU per year delivered from your 25 cords.
So far, so good, because the above oil vs. wood numbers crossfoot pretty well -- 333 MBTU from oil, 350 MBTU from wood. Also your fuel oil use was comparably in the same ratio as mine for my smaller same-vintage house, which is another good cross-check.
So now for the payoff. We'll say you need 350 MBTU per year, and coal will deliver 16 MBTU per ton, so you need to burn 22 tons of coal over the course of your heating season. So divide 44,000 pounds by the number of days in the heating season, and that is the AVERAGE pounds per day you have to burn. Multiply that by perhaps 1.5 because you will need more heat on colder days, so your system should be sized for that. So if your heating season is 150 days, the calculation is 44,000 pounds divided by 150 days, times 1.5 for the colder days, and TA DA you will have to burn 440 pounds per day on a cold day, much less on warm days.