Here is the final answer that was posted a couple of weeks ago:

However, when I needed to get some replacement parts, new grit,
etc., I never
got a response to any of inquiries to North Coast.

Looking at the North Coast cabinet carefully, I found a reference to
Cyclone
Blasters, who I believe actually make the booths and sell them to
North
Coast. Check them out at:

http://www.cycloneblasters.com/

They were very helpful and service was excellent. Now, back to
building
steam era freight cars.....

Several freight car modelers also recommended the sand blasting cabinet
available from Harbor Freight.

I haven't purchased either yet myself...

Jack Burgess
www.yosemitevalleyrr.com