Woof, I reckon you have given that old battery every possible chance to either recover or go into orbit, it's been beaten cooked fizzed, and a good old fashioned electrocution at 80v or more.... what else can a man do??
So I don't think you will toss it out wondering if you could have done more.
It does gell with my feelings on battery recovery from the dead..... it's a lottery, no science at all, something either works or it doesn't. Any time I have tried, I have met with the same resounding success you have just displayed.... none, nix, nil.zilch etc etc.
Some other folks have been wildly successful, and I don't ......totally ....doubt them, it is just that I haven't had any success at all, and struggle to see how they have blitzed me so bad..... so your results mirror my own attempts.
Anyway, onwards and upwards, the system is getting back together, thats the main thing.
Go woof
........oztules