Not in the last few weeks, no. There are a few scratchbuilt (well, with modified kit components) styrene wagons that can be found on my workbench thread - all 4mm, I'm afraid - which you might be interested in:
4mm - An EM Workbench: A 3F indulgence
Otherwise, here's something which may, or may not have fetaured. it isn't exactly a scratchbuild since the chassis is modified Parksdie but the body, if you can call it that is. This is one of a pair of Coil S that reached this stage quite quickly and then stalled because I need to make a jig for the metalwork (it was L section steel and angle on the real thing:
BR Rod Coil S - open merchandise conversion KSV). The plastic is the easy bit, it's the metal work and making a couple of loads of rod coil from a spool of 5 amp fuse wire that's putting me off currently...
My method for scribing planks differs from yours in that it's rather low-tech; I mark up using either a pair of draughtsman's dividers or digital Vernier callipers - these can also be used to scribe the lines. The dividers are good because they ensure the planks are a consistent width, but usually I simply use the point of a scalpel in the same way that Geoff Kent employs his scraperboard tools, i.e., perpendicular to the line of the plank rather than in line with it which gives a nice 'V' shaped groove. The sides are them cleaned up with a bit of fineish abrasive paper and the planks tidied up with a combination of a scalpel blade, finger nail and, sometimes, a glass fibre brush. this process gives about the right amount of relief and texture for 4mm, i.e., not a lot!
Adam