The one other circumstance that I can visualize is usually that it could be a standard Model 70 barrel and action by using a substitute XTR stock. This is certainly unlikely although...I think that it's while you describe, an unmarked XTR. The bottom window is shut via the doorway in https://winchestermodel70classicf93692.designertoblog.com/58072640/a-review-of-winchester-model-70-xtr-featherweight-value