Sega 
Megadrive motherboard re-cap
Parts and labor: £30
Megadrive 10Mhz overclock
Parts and labor: £30
Includes fitting a switch to the outside of the case, placement as per client consideration. Causes issues with 6 button controllers.
Megadrive region switches
Parts and labor: £30
Includes fitting a switch to the outside of the case, placement as per client consideration.
Megadrive RGB triple bypass
Parts & labor: £50
Involves lifting pins on VPU, removing traces, re-wiring the outputs.
Re-solder ports: £15