My 300d wont start when its cold out...

When it's below 50, it will NOT start without being plugged in, and on the charger for 5 hours. It's been sitting for 7 years, and hasnt had the valves adjusted in 8000 miles (should be adjusted yearly, or 12000 right?) The glow plugs are getting juice, but not sure if they have enough (and I have the seared finger to prove it).
What I have done to it since I pulled it out last year (and it's had the no start when cold problem since then) is this...
New battery (1200 CCA... enough to crank for 30 sec)
Changed oil/filter
Changed ATF/filter
Changed coolant/replaced hoses (not heater hoses... oops, but theyre in good shape)
And I've been doing an italian tune up when its warmed up with seafoam in the tank... I will do a quart of ATF in it if it warms up ever

Heres a story on what happened a week ago... Plugged it in and charged it overnight, and it started. I ran around for 30 min (without shutting it off) and stopped for fuel. I shut the engine off, pumped, and then paied... Got in and cranked it, and It did not start after 2 attempts spaced a min apart...

So please help me, I need this car a week from monday, and I need to trust its coldability...
Thanks alot, I REALLY appreciate it
~Nate