Give the hair a light grey paint "wash" to approximate the salt and pepper hair Troughton had then. A few grey warts to face and forehead . Glue some orange/pink bushy fuzz to eyebrow region after painting brows light orange.
The figures contained in the Custom Showcase are not for sale by Figure Realm, and the creators of the customs are no way affiliated with Figure Realm. The Custom Showcase is purely for entertainment purposes and only provides a means for the creators to show off their work and trade ideas. Figure Realm does not make or sell customs.