Weaver honestly lucked out a bit and faced a green Ruddock who was trying to jab and move, the Ruddock of early 90s would punch his head across the ring.
When they fought, Weaver was a 35 year old who was punching on memory. Ruddock, on the other hand, was taught fundamentals and was a nice boxer being trained by George Chuvalo. It was sometime later that he discovered his left hook/uppercut smash and abandoned all defense and fundamentals. If both were in their primes, Weaver's gas tank was always set for 15 rounds, however, he was a slow starter. I wouldn't be surprised if he could be caught in those first 3 rounds. I also wouldn't be surprised if he did get past those early rounds, that the playing field evens out.
When faced with the same 1986 Mike Weaver that fought in actually yes. But this thread is asking for the 1979 rendition
I think prime Weaver would have a real shot. Not that I’d bet money on any outcome. Either way it would be a fun fight to watch