I just had my control yokes inspected and refurbished by Saircorp.
www.saircorp.com
I didn't have push to talk buttons on my original yokes and had just used some after market velcro attached units. Saircorp drilled my outside horn on each yoke and installed a nice push to talk button and then wrapped the whole unit with leather. The wires for the push to talk are inside the leather and look really cool. It really tuned out nice, they even refurbed the emblems. When I retro the panel I will replace the custom Cessna wood finish on the emblem with a graphic that blends with the interior or panel.
Cost was about $650 for the pair.