We're all familiar with the Epoch system for railway timelines, so I was thinking of a similar system for British Outline N Gauge vehicles. This is a personal observation covering my time in the hobby from approx 1978..

Epoch 0 - Anything before 1970 such as Lone Star, early Minitrix and Arnold

Epoch 1 - 1970 - 1980 - Peco Jubilee / Wagons, Graham Farish up to and including Class 08, Minitrix, Lima - Langley and MTK kits

Epoch 2 - 1981 - 1995 - Graham Farish "Golden Era" - mainline diesels and electrics, Mk1/2/3/4 coaches, Minitrix A4, A3, Teaks, Lima CCT / Syphon (before leaving the market)

Epoch 3 - 1995 - 2004 - Graham Farish transitions to Bachmann - Class 170, V2

Epoch 4 - 2005 - 2010 - Dapol Enter Market with 14xx, Class 73, HST - Farish introduce high quality models made in China

Epoch 5 - 2010 - Present - Bachmann Farish and Dapol producing high quality models in China, new innovations in marketplace such as RevolutioN crowdfunded Pendolino - 3D printing changes kitbuilding market.

Just a few thoughts...