- General
- Technical Questions about Forum Operation
- Main O-Gauge Board & D56 Club
- Main Classic One Forty Three Board
- Main North American Brooklin Collectors Club Board
- Real Trains
- OGF University
- Buy/Sell
- Legacy/TMCC/DCS
- Tinplate Toy Trains and Accessories
- 3rd Rail Division of Sunset Models
- Evans Design Model Lighting Products
- Mega-Steam Smoke Fluid
- Hi-Ball Graphics-Model Railroad Custom Decals
- River Leaf Models
- Nicholas Smith Trains
- Gargraves Trackage Corporation
- Menards