Although his fabrication skills are excellent....they've been out for DECADES......He certainly isn't the first one to build a single round tube lower control arm.
I got my inspiration from UB Machine....20 years ago (I'm still a customer)
http://ubmachine.com/lowerround.html
Do a little research.....check out Bob's Pro Fab, been building and selling them for years. .....someone even pointed that out to JR in one of the early posts in his thread.