The chassis is pretty much as simple a beast as it could be - there are two sides which you put bearings in and then sandwich around some spacers.
The only problem is, choosing the spacers. Now this is a kit shot down from 4mm scale. The original had OO and EM/P4 frame spacers. You might say "the gauge is the same, use the OO ones" but you'd be wrong. They have got narrower as part of the reduction process.
I did a little measuring and worked out that if I used the wider spacers and then took quite a lot of the meat out of the "brim" bit of the top hat bearings, them I ought to be OK. Or at least if my back-to-back gauge is correct. The trouble with Gibson wheels is that they don't like being taken on and off the axle so I won't know for sure until I put them on properly.
Anyway, I fitted the bearings easily enough, only the tiniest amount of hole enlargement was required and the tapered reamer quickly dealt with this, and then the whole lot was placed on the Hobby Holidays chassis jig to make sure it went together nice and square. Only the driving axles were jigged, the jackshaft will have to take care of itself.
I have a couple of criticisms at this point. Both are more preferences than actual complaints and neither impedes progress. First, the brass seems a bit thin. I haven't measured it but I prefer something a bit thicker for chassis's. In fact I prefer nickel silver which is a lot less flexible but can see why we have yellow metal here. Second, the spacers are located with half etch lines in the chassis and I much prefer slots and tabs as they are more positive. OK, so the hiding the join is harder but I feel it's a small price to pay.
I'm sure most people will disagree and that's fine. neither would put me off buying another one of the kits (I rather fancy the Clayton...) though.
Final point, the top corners of the chassis have been snipped off as under the footplate there will be a fillet of solder holding the buffer beam in place. You won't see the bodge and the extra metal will make the buffers stay put.