the check valve on my Turbinaire mini pro has finally given up, I went online in search of a replacement with no luck, I understand that parts for this gun are no longer available, but I thought a check valve was relatively a standard part on most Hvlp guns, I thought I found some from Apollo, but those were to small. the connecting hose is 5/16″ od. I thought maybe somebody has found a supplier that’s hidden away a stash of these seemly obscure standard parts, Thanks Nate