Yes I know where they got it. Some wild game place in up state NY. They sell it but the price is to much for what you get. Plus I have my deer at the processor so making a 5 pound batch should be easy. I plan on doing what you suggest. going to check costco for dried blueberries and if they dont have them then Amazon will be my friend. Also read somewhere about a oz of wine per pound.
Last visit to costco I picked up 5 pounds of very fatty pork bellies. Plan on grinding that up to mix with the venison. If memory serves me right I used 2 pound to 3 pounds of venison.