Don't know what happened there...
You are asking a somewhat complicated question, it all depends on how you intend to make the wine. If this is de-stemmed already, you can assume 60 to 65% of the weight will end up wine. Assuming 10% was lost in racking that means you started with 132 to 143 gallons of must. (If you press hard you will get more.)
Using that I get around 20 pounds to raise your must by 1 brix. I'm using 17 grams per liter to equal 1 brix unit
143 US Gal
* 3.785 = 541 L must * 17 g =-9201 g sugar/453.3 (g/lb) = 20 lbs sugar to raise 143 gallons of must by 1 brix.
It's common to not add sugar to the grapes if you press before dryness, it's added once you know how much must you have. Don't add it dry either, make sure it's mixed in either a batch of must you pulled off to mix or in water, either way make a syrup.
I would suggest you check my work considering your investment and download Lum's book, it will get you through all of this with ease.
Joe