worth repairing or using again

I hope your transmission isn't full of water too!
There's always hope. Yours' can be rebuilt in B.C. by a long established converter rebuilding company in Langley. They probably have a rebuilt unit on the shelf. It's interesting that you've got a low stall stock unit and are going to replace it with a 3000 stall.
Is the 3000 stall matched to your engine-drivetrain combination or not.
Just wondering.