Would a 4.5x114.3 lug spec fit a 5x115?

No, a 4.5x114.3 lug specification would not fit a 5x115 specification. The first number indicates the number of lugs (4 vs. 5), and the second number represents the bolt circle diameter in millimeters (114.3 vs. 115). Since both the number of lugs and the diameter differ, the two specs are incompatible.