Ref the 2 shops mentioned by Lakeshore: Phill's is on Nile Street. This is a one way street with limited parking, which is chargeable by the minute i.e. 20p gets you 20 minutes etc..The staff at Phills are very helpful and won't try to convince you to buy stuff you don't need, and their advice is free !
The other model shop,GLADSTON'S, is on Bedford Street, just a short walk from North Shields Metro Station - in fact, when you exit the station you will be virtually half way between the 2 shops, should you decide to visit them both.
There is also a wholesalers premises on the Tyne Tunnel Trading Estate (High Flatworth) known as BAY PLASTICS. They sell full sheets of plasticard (referred to by some as "styrene") I bought one from them for £7.20p. That particular sheet was 1.5mm thick. I've cut it up now but I think it was 6ft x 2ft 6in or thereabouts.
http://www.phillsmodels.com/ http://www.gladstons.com/shop/ www.bayplastics.co.uk Regards,
Ray.