I thought I'd update this thread since I recently bottled the batch. After my attempts to restart fermentation I pretty much put the fermenter in an upstairs closet and forgot about it for many months. I was about to dump it since I needed to reclaim the fermenter, but I gave it a taste first. Although it is still quite sweet, something magical seemed to happen. The alcohol mellowed out and the sweetness (while still there) rounded out quite a bit. It seems to be in the ballpark of a cream sherry, and is a real nice sipper now. FG is now down to 1.050 (it had initially stalled at 1.058).
Here are my tasting notes:
Appearance is ruby/copper with some haze (I never ended up fining it). The nose is vinous, with a big sweet maple note. There are hints of vanilla and dried fruit/raisins. There is also a woody cedar/oak note.
On the palate, it is winy and quite sweet, with a lot of maple syrup character. There is a moderate acidity that helps balance the sweetness. Alcohol is notable. I also pick up some wood, vanilla and a sherry/raisin note. The mouthfeel is full with some juiciness and a bit of tannin. The finish is drying with wood and maple lingering as the juiciness starts to fade.
Overall, I am pretty happy with how it turned out. I think the complexity is just starting to develop now and will hopefully develop even further over time. I was surprised how much wood I picked up, but I'm guessing that using good quality grade B syrup makes a difference here. I''m glad I went with 71B for my yeast choice, since this really needs some acidity to balance out the sweetness.
I doubt if I'll brew this again, since it's a real sipper and the stockpile I have will likely last a decade at the rate I expect to consume it. If I did, I think I'd still try to shoot for 1.020-1.030 range for FG. I think it would be a lot more drinkable down in that range.