When I was building it, I couldn't face the cost of a stainless needle valve and didn't want to use brass so I got thinking how I could make something similar myself.
Anyway, after testing it out on two cleaning runs and one spirit run it has performed well so I thought I'd post a pic on here in case anyone is interested in making one.
The flow rate can be adjusted quite accuratley.
Its very simple really, It just comprises of some 6mm copper tube(same as I used for condenser) and a 5mm A4 stainless bolt.
Here is a pic:
Click on the image for the large version
Please shout if anyone would like any more details on how ho make one