The last model shop worth going to was the county house opposite the centre for life in Newcastle.
One of the lads that raced with us worked there so he would order us anything we wanted. There is a shop in Whitburn that, again can get mostly anything but they are not the fastest in getting orders together.
I find it just as easy shopping online and normally get the orders within a couple of days.
Good luck in your venture but shopping online beats trailing to a shop to find that the bits you want have just been sold etc!
If you fancied getting a warehouse and building an off road track inside with a shop attached then i would say that would be a good idea! Good luck
