This is the one piece nylon link that's on my 850 now.
Scale Art has a one piece cast metal link.
That's what can be bought for 14th scale. IHSteve has machined his own track parts in steel for his dozer. Other builders, like RCLogger use K1 attachment chain & bolt on their own selfmade pads. McMasterCarr, as well as others carry that chain in various sizes.