1967 Mercedes Benz 280sl troubleshooting 'white smoke out t

Engine Mechanical problem
1967 Mercedes Benz 280sl 6 cyl Two Wheel Drive Automatic 190k miles

my wife noticed a 'funny noise'' from the engine and 'white smoke' coming from the tailpipe after she stopped. There is no coolant, but also does not appear to be any water on the dipstick. I'll add coolant and check for oil, but I'm thinking head gasket is the only way that water can get into the tailpipe, yes?

any hints on how to troubleshoot? How big a deal am I looking at? What other damage should I be on the lookout for? Is this a 'talented DIY' fixit job or one for the Dr. Mercedes specialists?

thanks for your help.

td