I'm glad it worked out ok. Was there any damage to the mechanism?
FWIW, therother and I killed a 'free range' Wither once without much difficulty. We used fully enchanted diamond armor, heavily enchanted bows, and chugged a few potions before we spawned it. I think the thing died in about 30-45 seconds. So, it's very doable if you have the right kit.
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