@Megan; you did the right thing by posting it here. Folks will keep an eye out for it. But, without a serial number, reclaiming it might be a problem if it is found. Is there ANY chance that GTBR has a record of the sale that might include a serial number?
As for filing a police report, I'd say yes. That way, if the bike is found/recovered they might know to contact you.
Both suggestions are longshots, but you have to get lucky sometime!
And for the rest of you out there, when's the last time you got a good clear photo of your bike? Recorded the serial numbers? On all your bikes? Today might be a good day to catch up on those chores, if necessary..... And no, I do not yet have a photo OR the serial number of the bike I bought from Ian last week, so this is a reminder for myself, too.