They arrived yesterday.
Worth the wait? Absolutely. They are splendid, great detail and (important) quite different to anything else you can get RTR in LMS.
According to the LMS Carriage Society (yes, there is one!) the Stove 'R' was "used on parcel, newspaper and milk trains, which often went attached to passenger trains." It was designated BGZ code in BR times, or CR in LMS days.
The N Gauge Society Stove 'R' was produced by Dapol. Produced in different running numbers in LMS livery: my wagons are 32975 and 32977.
Here are some photos:
These next two photos show the colour difference between the Stove R, produced by Dapol, and the Graham Farish Stanier coaches. Quite a difference and the roof colour is very light on the Stove R.
And the real thing is on the Bluebell Railway here.