Yellow jacket referee

[Clockmaker]

Can anyone help with the name of the ref who wore a yellow jacket and one of the matches he wore it?

[Mark187187]

John Williams wore yellow in the 1979 World Championship final. Also for John Spencer vs Perry Mans in the first round 1978.

[Clockmaker]

Thanks. It has been bugging me for weeks trying to remember. At 73 the brain is a bit slow.