Though my experience with all grape wines is limited to what I've read,I've read a lot and have a few varieties on order to be picked up soon...
Your 75# of grapes will net around 4.5 gallons of juice and your barrel is 60gallons... I'm guessing you are doing a red?
While you may be able to primary in this, you would certainly not want to age any wine in this for any length of time. And you will be transfering to a secondary fermenter, too, right? And then a third? You'll end up with 3-4 gallons in the end. Use carboys with a stave of oak if you want some oak flavor.
Next year order more grapes (like 1,000#) and use the barrel to age the wine, not primary.