The Windsor trademark was a House Brand for Montgomery Wards around the turn of the century (circa 1890s to mid-1910s). These beginner's grade acoustic flattop guitars and mandolins were built by various American manufacturers such as Lyon & Healy (and possibly Harmony). Source: Michael Wright, Vintage Guitar Magazine.
Instruments previously produced between circa 1890s and mid-1910s. See chapter on House Brands.