Chris, while you could do that, the phrase "Silk purse sows ear" comes to mind.
Depends on whats wrong with it . . . I would hesitate to guess that it is somewhat insipid, low in colour and possibly alcohol or if you corrected the grvity with sugar, its incredibly dry kick like a mule and tastes of pretty much nothing?
What I would be tempted to do would be to make up a robust red, and while it is fermenting, blend in the poor quality wine over the period of a few days. . . . The only danger here is that you end up turning what could be a good red wine into an average/poor one.
I would go with something like
2 1/2 lbs dried elderberries
8-10oz Concentrated Red Grape Juice.
Sugar to bring the gravity up to 1.090.
Ideally you want the 'new' wine to make up 2/3rds of the total volume of the mixed wine so if you have a gallon of RGJ Wine then you need 2 gallons of new wine.