In the driveway near an intersection there is a de-glassed flat bottom Westinghouse OV-25, and there is another flat bottom Westinghouse OV-25 (with original glass) in a university parking lot. What’s interesting is that the fixture near the intersection has a different font embossing on the optical door (a weaker, times new roman font) than the fixture at the university parking lot (a stronger,  impact-like font). The fonts read "WESTINGHOUSE TYPE OV-25". I am certain the fixture near the intersection is an early version of the 1st generation OV-25 and the fixture at the university lot is a later version (the lot opened in '62). If it is correct, which years were both versions produced?