Yes, that's the bit I didn't fit and no amount of squeezing would have worked I'm afraid, you see the original front end all comes away in one piece so the frame sections are wider than the main frame section behind so that bolster is also wider.
For my sins I've modified the frames to be the same width through out for two reasons, I struggled with the internal screws to bolt the two together in the original set up and my 3D internal motion bracket is the same width and does not have the joining plates in the way. It does mean the the front frame section is not scale width but that has the added benefit of the inside cylinder block being narrower and I can add the dished section on the inside and not limit the radius it can negotiate.
I did look at the cast bogie but some castings were quite poor and when I measured it all up found it matched the original kit front end frame width. Because mine are a couple of mm narrower then it would have looked odd poking out wider than the engine.
I don't subscribe to the scale width frames at the front when the wheels are not, the juxtaposition between the two is thrown out and it looks odd, if the wheels are narrower then the frames should be too, that way you maintain the correct visual offset between the two.
On the face of it, it's a lot of extra work and so far it has been, but the benefits come later and they far outweigh the extra work now, the redesign allows the whole motion section to be taken out of the engine to be worked on.
It also allows a much greater strip down and drastically reduces the painters time as he doesn't have to get in awkward corners or mask up. But most of all, it saves time when reassembling as there is very little motion in there and it can all be added afterward; as such there is little cleaning up of running surfaces and reduced risk of damaging the painted surfaces.