Pour a teaspoon of oil into each cylinder and check the compression again. I've heard that this can help the rings seal up a little tighter. Maybe enough to help with the start.

If the lower radiator hose heater is working then it should be enough on it's own. It is something like 600 Watts. The oil pan heater is only about 200 watts, plus it is about $55. The hose heater should be enough. Try throwing a blanket over the engine while the heater is on. It takes several hours to get up to temperature.

-Jim

__________________
1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.