RailNscale is actually a very active Dutch two man operation; unfortunately as the name suggests, mainly in N scale. Check here for instructions in english: https://railnscale.com/how-to-order/ Their paving tools are basically for N scale, but the N narrow gauge roller fits Z scale track. Check their instruction video: Another solution is using lasercut inlays; again, Nm scale product usable for Z. This website is in German only, I do believe they do ship internationally. Pricy but nice, this link shows the options for Rokuhan and its various radii, also available for Marklin track: https://spur-n-teile.de/einlage-rokuhan/ Also for turnouts ("Weiche") available. For instructions: https://spur-n-teile.de//media/products/160418_anleitung_pflastereinlagen_n-tram.pdf Matt
I like the idea of a 4-wheel Marklin flat car better than a boxcar. The lower center of gravity and the flat surface to press down on seems like the best way to do it. The 4 wheels means less derailing, too. I think it will work on clay as well. Jim
