David 
I brazed mine the old fashion way. They are common failure points for the factory tents those corners are. Replacement parts are only available used and usually not piece by piece. 
You may do okay to bring it to a place that does custom canvas work. If anything they could point you in the right direction. 

Bill-with a VW driveway side tent that takes up to much room
       and never used....

On Jun 25, 2012, at 1:02 PM, David White <sirgrumpsalot@GMAIL.COM> wrote:

> I have one of the yellow and blue "circus tents" from VW. One of the
> metal corner frame pieces is cracked. Does anyone know of a company
> that either repairs tent frames or can make replica pieces? Thanks.
> 
> David