Hi good skills, the only problem is that the home made actuation arm may cut down on the turbo flow rate as the Turbos when manufactured/reconditioned the actuator functions
are set up in a flow tank using coloured smoke and measuring devices for airflow, I was privileged to watch one of my turbos being rebuilt at a local specialist, you don't appreciate how precise these things are until you watch the calibration process as the slightest adjustment of the actuator arm causes quite a dramatic difference in the flow rate across the rev range.
I think Steves idea is a good one as a stock arm because its rose jointed would definitely put you nearer the middle of the ball park and at least the remainder of the old unit could be reconditioned for use another time or sold on if you don't use it, my old 2.2 Mondeo turbo I had reconned I never used it it cost me £360.00 to have done and I recently sold it on a Ford enthusiast site for just under £500.
Steve.