Keg Post Thread Size

I am looking for the thread size of the post on my kegs (ball lock Cornelius). I have seen a few sources for this, but just wanted to see if anyone had any personal experience with it.

Essentially I would like to attach a ball lock gas-in body to a barbed adapter to attach some tubing to the end to use for pushing beer and purging bottles, etc.

Morebeer sells something similar to what I would like to build:

http://morebeer.com/view_product/18228/102295/Gas_Body_Connect_x_1_2"_fpt_Coupler
but I would like to have a barbed fitting and not have it cost $34.

Here's a link with the thread sizes:
Link

It sounds like this is not a common thread size so you might have a hard time finding your own fittings. I saw one message from someone that was a machinist who said they were even having a hard time finding a 19/32" - 18 tap.

Perhaps you could make friends with a welder and get them to weld a post fitting to a 1/2" half coupling for you.