If you cut the strip off, the remainder be left sandwiched between the two pieces of wood? Will there be enough room to install additional weatherstripping, or could you use pliers and just pull it out? If you have to use tin snips, BE CAREFUL, the metal left will be as sharp as a razor blade (insert voice of experience here).
OB has gone to a gun show, I'm doing wash and surfing, seriously considering beginning ironing, maybe I'll look for something to eat first....
I was planning on leaving the sandwiched part between the wood. I could try filing the jagged edges down.
I expect to find some rotted wood behind there...not a lot because the frame itself isn't squishy from the outside. I was going to fill with that epoxy resin stuff.
I was studying up on weatherstripping for awning windows. It looks like v stripping attached to the frame, not the sash, is the way to go.