Very interesting, Tom.
Prior to laser cutting, the original kits were CNC routed, which removed the top skin of the plywood from between the beading.
Something of a revolution, avoiding handling the delicate fret.
BUT... the routing tended to leave rough edges which were quite difficult to sand smooth, and affected the finished paint job.
(I guess you saw my pic)
This is the first close up I've seen of the new versions. OK there is a delicate fret to handle, but they do look good.
I always liked the concept of the kits being complete with wheels etc.
In terms of building tips, the coaches look like they have straight sides and I can't see any real problems.
The original bow-sided versions needed a bit of ingenuity like gluing the bottom edge first, before trying to curve the rest of the side.
I recently bought IP's roof fitting jig, and it's worth considering.
It forms a cradle, and the coach body is laid upside down on the roof panel, and weighted down until the glue sets.
If you want the roof to be removable, you make a frame to fit inside the body top edges, and use it on the jig in the same way.
Happy gluing!