Coastal: I agree that you drastically underpitched, but....
If you are looking for an ale-type vigorous fermentation with lager yeast you'll be disappointed. My "Soxtoberfest' brewed back on November 24 was pitched with 3 qts. yeast slurry from a Vienna lager- in the neighborhood of 400billion cells calculated. Pitched at 48 and fermented at 45-50 until d-rest time. She took about 48 hours to show any burps, and then was a nice steady sedate blurp every couple seconds. Fermented down to FG in about a week and 1/2, then D-Rest and lagering. Bottled 1 week ago, and she was beautiful.
Your underpitching has led to a longer lagtime because the yeast had to build up their numbers, and it might lead to more off-flavors. Definitely should give it a Diacetyl rest to help clean up off-flavors, and then might even consider leaving it on the yeast at a higher temp. for longer than normal(say a week instead of 2-3 days) before racking it for cold lagering.
Primary: Batch 50 Bock, Winter Solstice Moon,
Cold Conditioning: December Marzen, Black Friday Vienna
Bottle conditioning: Ben's Doublealt, Jim's Altbier
Drinking: Gunslinger Cranberry Graf, Waldo Lake Amber, Loghouse Honey Porter, Labor Day Irish,Apricot moon, Ryecentennial PA,Caribou Slobber, La Fin de L'Annee, Das Terminator Dopplebock, several others