I'll start with Mervyn Day, probably most famous for being West Ham's young keeper from the mid to late 70s although he made more appearances for Leeds than West Ham and was amongst the Leeds squad when they won the title in 1992.

Seems to have followed up his playing career with a successful management run, took Carlisle to promotion to division 3 (or 2 as it was then) in 1997 and won the FL Trophy with them before falling out with the chairman. He then partnered Alan Curbishley at Charlton until Curbs left and then went with him to the Hammers. Last involvement in the game I can find was as a scout at WBA which he left in 2015, surprisingly he's still only(!) 66.