There's good news and bad news regarding the couplers on the Accucraft C- 16. The bad news is that they're about 1/4" too low, and it turns out that getting the coupler pocket off the buffer beam is @#$% near impossible. You'll need a minuscule nut driver, an magnifying visor, good light and some luck from what I can tell.
The good news is that the knuckles are easily exchangable with Kadees. Luckily, I had one of those knuckles that are offset upwards (it's one of the 83X series, but I don't remember which one). That knuckle comes out at just the right height when mounted in the Kadee pocket. You have to drill out the hole in the shank to 17/64" to fit over the post, but otherwise it's just a screwdriver upgrade. So, if you have or are getting a C-16 and need to pull rolling stock with an accurate 1:20.3 coupler height, that's a simple solution while you search for a place to buy that tiny metric nutdriver. regards, -vance- Vance Bass Albuquerque, New Mexico, USA Small-scale live steam resources: http://www.nmia.com/~vrbass