Reb Head,
I’m very sorry to hear about the summons. It would be a shame to have to pay so much money that could otherwise be used for better purposes.
I suggest that you look the summons over very carefully noting even the slightest mistake, but regardless of the accuracy you should try to dispute the summons. The Department of Finance may offer to remove one third of the fine if you plead guilty.
Please have a look at the “Alternate Side Parking Rules Suspension Calendar” http://www.nyc.gov/html/dot/downloads/pdf/asp2008.pdf and note that “Double parking of passenger vehicles is illegal at all times,
including street cleaning days, regardless of location, purpose
or duration”.
Good Luck!