Bought a case 8, of these little beauties some time ago. What run they have had has been on a10’ dia. curves. Cold this winter in H town. . Set up a Christmas tree type layout w/ 4’ d curves, S’s these cars would not make the S’s axle CL part of the problem. Needed to enlarge the pocket for the link to move more, RL? Quick fix, replaced the link w/ a -113 O-ring, enough flex to allow easy transition in the 4’ d S’s. Anything -113 to -115 O ring should work. Local rivet counter came by, “free beer + stir crazy”. Criticized my loads, side boards, lack of weathering the 2-4-2 etc. complimented the use of link coupling, “period &type correct”. Never know?