Here are the versions that I THINK you are asking about? With the square rivet on one, and a spot weld on the other? If that is what you are questioning, both traps are indeed #48 Newhouse traps, just from different eras. I'm no expert, but if you want to learn more about these traps history, you can post questions about it on the trap collecting page. From what I recall though, I think once Newhouse production moved from Oneida to Animal Trap Company of America in 1925, from that Era forward, these traps would have transitioned to the spot welded cross, and I think perhaps also they transitioned from the flat link to kinkless chain around the same time frame. #48 Newhouse traps were made until 1976, so the newest ones with the spot welded cross are already 50 years old. The youngest ones with the square rivet are AT LEAST 100 years old. The base from these traps would also be compatible with a post and jaw set from #4's and #14's. Since all three traps ( #14's, #48's, and #4's) had compatible parts, there was a lot of trappers that would use parts from other traps, as components broke, or were lost/ damaged due to a catch, etc. The #14 jaws were a toothed offset jaw, so you may have a trapper modified trap, if the pan says #14, but the toothed jaws have no offset ( these would be #48 jaws).
However, I believe during some time frames, and certainly during this transition period, since all components were interchangeable, some of these traps were factory original with pans of other sized stamps, placed on these traps, that don't correlate with that jaw set on said trap.