We've been trying out the prototype FR bogie I made up a couple of weeks ago.
Himself has attached couplings and given the pair a coat of black paint and installed them under our new model of 116 to see how they look.
As I expected they need quite a bit of packing to get the ride height the same as with the plastic bogies we've been using, although it varies from carriage to carriage.
(It seems I'm no more consistent than Boston Lodge in the way I build them!)
It doesn't necessarily show on the model, because only the bottom half of the bogie is usually visible on FR carriages, but if we're going to try to fit these as replacements throughout the fleet then it could have consequences if the old pivot bolts are not long enough.
So I've decided to get a Mark II etch designed which will have the stretcher beam 1.5mm higher which should reduce the need to for packing.
It will mean going through the process of making another master for the resin cast of the axle box and suspension details but it'll be worth it to get it right.