I bought mine used off of eBay....not long ago I saw a NOS add on cam saddle for sale on EBay for $35.00....per saddle....
I had a hitch head failure and replaced my straight bars with bars with the crooks in them...like a dummy...forgot to take the add on saddles off before I had the old WD recycled.
So...I have the u-bolt cams...but no saddles now. Lol...
PPL motor homes had some NOS kits...they were over $300.00 last I checked...
As you can probably tell from my language... This product is out of production now...
BUT...dual cam will not magically make a bad handling trailer good again...
I recommend getting your brothers hitch dialed in now that he has...weigh the rig and the trailer tongue weight....guessing does not work well.
You may find his bars are undersized or something like that...
Thanks!
Jeremiah