I have acquired several old Winchesters that spent some time under water after a flood.  Disassembled and got them in pretty good working order.  Thinking about breaking them down and doing a complete refinishing job.  Wondering if anyone has any expertise on what action wrench and barrel vise would be best for this job?

I believe most gunsmiths who re-blue leveractions. Don't separate the barrel from the receiver.

Of the 'smiths I've talked to about rebarreling almost all agreed they made action filler blocks for the various lever actions they've worked on. Seems compressing the sides and twisting the action was a worry for them. I have no first hand experience, just passing that along.

I made this wrench last year from 1x2 stock for a Marlin project but you can buy something similar.  For a vise I have a Wheeler unit with the wood blocks but you have to use rosin or the barrel will slip.  The type with aluminum inserts grip tighter but cost more.

Prior to removal you need to think about how to support the frame.  Some guys mill an action block but with a Winchester you can probably use the bolt itself.  Just make sure to place an index mark where the barrel meets the receiver to line up the parts during reassembly.  For guns sitting underwater I would soak the joint for a few days with some sort of penetrant.

FWIW the process is pretty straightforward with the right tools but I would refinish the guns as a unit if you can.  Good luck...