The number stamped on the steel base looks like 88. if so, it is a Redfield and fits Winchester Model 88 and 100 rifles. Uses turn-in style ring set. It is missing two windage adjustment screws at the rear, however they are easy to find. Leupold, Burris, Millet, all use the same system, and are readily available.
The alloy base is a Weaver, and by going to their website you can reference the number on it to the several rifles it can be used on.
The plastic drums are calibrated bullet drop indicators for the elevation adjustment on a scope. A bit hard to tell from your picture, but most likely Bushnell.
Ted