I'll maintain a list of manufacturers and suppliers as I get informed. Please email of PM any new suppliers, etc:
http://www.TGauge.com – Dealer and distributor of Eishindo products as well as manufacturer and supplier of a variety of T gauge products worldwide.
http://www.gssmodelengineers.com - Distributer of T gauge components in Burnham-on-Sea in Somerset, England.
http://Trainaidsa.com - Distributor of T gauge products in USA. Website doesn't indicate where they are, but I've been told they are US.
MODERATOR EDIT - Site not available as of September 2016. It is reported that the owner has sadly passed away.
http://Trainaidsa.in - Distributer of T gauge products in India.