Hi Kevin,
I don't know for certain, however it's very unlikely that they'll use proprietary parts. (it would cost a fortune to develop and have manufactured for one!) Its much more likely that they've got something off the shelf and slapped it together.
I need the length and the fitment type (square, octalink, splined etc) then I can work out what you'll need and try and grab you a link.
No need to have 100% matching arms as long as they're the same size and type then you're fine!