Danbuoy

Not sure if my original question got lost so apologies for reposting....

Its a friends Escort 1300xl ~1975, asked me to look at it. Car professionally restored 2yrs ago with complete engine strip. Recently car overheated with water from overflow, contacted restorer who has moved and unable to look at unless brought over, I said I'd have a look albeit with mostly Triumph experience.

Temp gauge didn't work, top hose and rad felt warm. Put new temp sensor in, gauge registered as it warmed up but coolant flowed out before "normal" and this time top hose/rad cold. Took stat cover off and was staggered to find it was coated in a black gunge. It cleaned in water and lots of black bits and sediment in sink, tested and ok. Put back and this time all was much happier, maybe the gunge was shielding the stat? However (apart from recommending a complete flush and new stat to be safe) unsure what caused the gunge - could it be head gasket with head oil feed getting in? Any ideas welcomed please.

Cheers

Paul

ps - Ford owner and lots of Fords in the past!