THANKS to all for your replies. I did locate a die at www.tapcousa.com by using their 800 number and giving them the above specs. They have two in stock which I left there since they wanted $136.00 plus shipping to be relieved of one of them.
As someone mentioned, I can replace all my hoses for that amount.
I do have a standard pipe re-threading set and used its file with the #12 grooves and it worked quite well but left a rough finish. I smoothed it out a bit with the wire brush I use on my BBQ and it ended up looking good. The problem I had before all this was that it would not screw into my plastic quick-disconnects without serious binding. All is well now helped a bit by silicone grease.
For those interested I did find an external threader (11.5) in the Mc Master catalog but it was $89.00. A bit better than $136 but still a bit expensive.
Again .. thanks to all.