I just ordered and received the Brutus plans in the mail. I've been reading over it the past couple days. It seems like he built this a couple years ago and since then materials and costs have changed. For one main example, the ASCO red hat valve he said he found on ebay for $57/ea. He even gave model # SC8210G37. Do these not exist any more? Also, according to the ASCO website, they are listed for water/air use. He is using these for gas? Also, it looks like if you can even get this model any more each one is upward of $400! Am I reading this wrong or has something changed?