Keith D-tuner spline

[Shawn Parrish]

Greetings:  I'm trying to spline a new tuner buttons for my Keith D-tuners.  By measurement, a 5.5 metric triple square 12 point spline bit will work; however, I can only locate 5 and 6 mm.  So does anyone have an alternative spline substitute?  Does anyone have a non working Keith tuner that is not being used?  Thanks for any assistance.

[Keith Somerville]

Ultimately, might be easier just to get a replacement from Beacon unless you're making up something special.