Aluminum Sunroom Window Weatherstripping

I have 11 aluminum sunroom windows manufactured about 10 years ago. It seems the weatherstripping is worn & I get some freezing along the top header frame in temp extremes. Due to the crush or wear, it's hard to tell which size to order. The window track width is 1.260". The base of the strip measures .190" wide. The window, not including weatherstrip, is 1.122" and with the (worn) weather strip it is 1.215. These numbers suggest there is a gap allowing in cold air. There is a weatherstrip on both sides of the slider at the top.