At 10:55 AM 5/11/2012 -0700, you wrote:

Does the coupler pocket require the Kadee coupler draft gear? If so, you can
use a #178? If it only requires the coupler, you can use any Kadee centerset
shank semiscale coupler - the main difference between the #58 and #78 was the
draft gear.

http://www.kadee.com/htmbord/page78.htm - notice the different shape of the center and the coil spring. The SC&F and RYM resin kits have a molded coupler pocket with that type of setup for the coil spring. I am not sure if a 158 is a drop-in replacement or not. If not, I guess I need to go find more 78s pronto.

Andy