2A-Rail - 5.5mm 3D printed models on Shapeways.
Modelling 3 Foot Narrow Gauge on HO Track - shows what can be done for US slim gauge railroads in 5.5mm scale using commercially available models as a basis. A must for anyone with Bachmann 0n30.
55th Studios - The new home of the MSM range of kits.
C-A-Solutions - website design and maintenance.
Chris Ward 3D Printing - 3D printed locomotives and rolling stock.
Custom Model Decals - Custom Model Decals produce bespoke waterslide decals for modellers in many scales and aim to deliver affordable custom decals in as little as two weeks. 5.5mm Association Members can apply for a 5% discount.
Facebook Group - 5.5mm railway modellers group on Facebook.
Dave Etheridge - 5.5mm thread on RMweb.
Max Brayne's - 5.5mm 3D printed models on Shapeways.
Narrow Gauge & Industrial Railway Modelling Review - the UK's premier narrow gauge modelling magazine, published four times a year.
NGRM Online - an online forum for narrow gauge modellers in all scales and gauges.
Narrow Gauge Railway Society - for all real narrow gauge railways.
Narrow Gauge Railways UK - a list of all narrow gauge and miniature railways in the UK and Ireland.
Peco Model Railway Products - make 12mm gauge track and points suitable for 5.5mm scale.
Tebee Models - produce 3D printed 5.5mm scale models for 9mm, 12mm and 16.5mm gauges.
Worsley Works - make 'scratch aids'. These are brass etchings which make up into the shell of a model. No castings or non-etchable detail is provided, these must be added by the builder. Worsley Works produces items in many scales including 5.5mm.