Light switches with knob and tube wiring?

I've replaced all of my light switches in my VERY OLD house over the past few days with new switches. There is original knob and tube wiring going to most of them. I haven't had any problems until I replaced a light connected to 2 switches. The hall light at the top of my stairs is connected to a switch downstairs and a switch upstairs. One switch has 4 wires going to it and the other has 3 wires. Both new switchs are 2-way switches and have brass and copper connections on the right and brass and green connections on the left. Any ideas on how they should be hooked up?? I've re-wired them several times but can't get them working together. Either one switch works at a time or neither work.
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Brass Light Switches