300D no start, possible gelled fuel?

[aieeegrunt]

I have a 1978 300D that sat outside without running for about a week or so over the holidays. I had a trouble light lying on the fuel driver side most of that time. Plugged in a lower rad hose heater three hours before I needed to leave this morning.

Car wouldn't start this morning. Cranked and cranked most vigorously, but would not even attempt to fire. Recent glow plugs and valves adjusted in fall. The one thing that did catch my attention was this; usually with this car extended cranking success of fail results with a white cloud and a bit of a fuel smell behind it.

This time the air quality was conspicuously and suspiciously pristine. Did my fuel freeze in the lines? I toss a couple ounces of Diesel Kleen cetane + antigen (white bottle) per fillip in the winter. Does this car have a water seperator somewhere that froze up?

Thanks in advance