You arn't out much to give it a shot. You will want to stabilize before back sweetening. I would consider picking up a fresh yeast pack. Hard telling how long it has been in the garage.
Nice score by the way.
Reality is an illusion that occurs due to the lack of alcohol.
Give a man a beer, he'll drink for the day.Teach a man to brew, he'll be drunk the rest of his life.
I have 8 carboys, 8 cornies, 5-1 gal jugs, 200 wine bottles, 10 cases of beer bottles and a nice assortment of flip tops....My goal is to keep them at least 50% occupied