I appreciate you showing the problems and disappointments. It makes me feel better about my own failures, rather than being given the impression on RU-vid that everybody gets things right first time. Graeme
On my N scale layout I used Peco NB-26 Platform edging - brick type. They are made from plastic. These edges also come in a concrete style. As I have two parallel platforms that curve it was a lesson on using a hair dryer to bend the edging to fit the curve exactly. I used my longest carriage / loco and and pencil to draw a line on the baseboard to mark the curvature where the Peco edging would sit and glued down. I then used 1mm balsa wood as my platform surface that was painted light grey in order to represent an asphalt surface. Peco actually recommends using Ratio 308 flagstone (they are made from 1mm thick card), as the platform surface but I don't like the style - it looks like large paving stones and I have never seen any platform surfaces like that so for me a nice simple asphalt looking surface was the go. The end result looks very impressive but I must say, constructing curved platforms can be daunting. Always the chance of a carriage or loco scraping somewhere so extreme careful measuring is needed, more so with N scale.