I just got this cute little 1682 caboose as a thoughtful gift from some close friends!
Since the Razorback Traction Co. doesn't use prewar couplers, I decided that a nice knuckle coupler was in order instead. 
My first thought was to install postwar trucks...
...but I decided against it, as the coupler length wasn't quite right.
I opted to use a coupler scrounged from an MPC Alco FA some years back.
Since one end was already missing a coupler, I decided to install the knuckle at that end and retain the original coupler for the back end of the caboose.
End wall and retaining tab for the old style coupler.
Retaining tab folded down.
Two discreet cuts with a cutoff wheel:
And we're ready for the install!
I had originally thought to drill out the tab and bolt the coupler there, using the center rivet for the centering spring, but the coupler stuck out a bit too far for my tastes. So, a second hole is drilled for the centering spring:
And the coupler is bolted in place with a 4-40 nut and screw!
A bit of 1/8" brass tubing is slipped over the centering spring, as the tab doesn't quite reach...
And here's the finished product!
The 1682, escorted by the Giraffe Express' "Junior", takes a victory lap!
Mitch
