HI, I was wondering if you can offer any advice on the restoration of the windows in my sister's house. They are the original double-hung dating from the 1880's or 90's. Given that the windows have all the usual symptoms of age (a bazillion coats of varnish/paint/etc, broken panes, a few damaged sashes), we're removing the sashes for repair and to heat-gun the frames. The thing that's driving us nuts is a vertical set of metal tracks that, presumably, are not original. I'm guessing here, but I suspect somebody thought it would be really great to plane down the windows about a 16th or an 8th of an inch and install these tracks as guides along with a set of clips on the upper and lower sashes that would interlock to form a seal when the windows were closed. Both tracks and clips are now rather bent up and have been the cause of more than a few strings of expletives that, quite frankly, are starting to draw disapproving looks from the neighbors. The trick is that if we just toss the metal tracks, the window (now being a couple 16ths of an inch or so narrower than the frame) will rattle and stick. I'm wondering if anyone makes any kind of vinyl or nylon strip that could be used to line the inside of the windowframe in place of the metal tracks? I'm thinking this would have the advantage of eliminating most wood-on-wood contact in the windowframes, which should actually make them easier to open. Ever seen such a thing? Got any tricks up your sleeve that you'd recommend (aside from sending hatemail to the former owners, which we've already done)? Any help will be apprecited. I didn't find the right solution from the Internet. References: https://bit.ly/2xMkuq5 eLearning Solution Example Thank you.