Blackcurrant wine

[hads]

I've been given some blackcurrant wine, about 6 gallons of it. It's been sitting in the fruit since it was started last year and I've syphoned it off most of the fruit but still need to strain it a bit more. It tastes ok, lots of the fruit flavours, but not much tannins or body to be honest. First question is will it still be ok to drink having been sitting in the fruit for 6 months and secondly is it too late to add tannins. Don't get me wrong it's perfectly drinkable as it is but I've mixed it maybe 2/3 blackcurrant wine with 1/3 bought red wine and it's really nice. Is this the way to go. I don't know anything about the production, OG or what yeast if any was used.