I have the 1mtr version
It is very clever
I bought a length of heavy angle to make different sized bars for it
I am sure there is more tricks to it then i have learnt by sodding around with it
Once you hve seen one. I dont think it would take much to build, and for a lot less than they fetch
Mines a 620 & it has 4 braces, they usually have 3, not complaining, just that I've not seen a 620 with 4.
I'd say the brace is the hardest partSome poor ****** probably only has two. ;-)