Damn, very sorry to hear. As another Brompton owner, just wondering why you didn't just fold it up and take into the gym?
Did you register the frame serial number on Brompton's website? It might be helpful to have it handy in case you see one being sold on craigslist or ebay. They're relatively unique in NYC/Brooklyn so you might have good luck spotting it being shilled off. I'll definitely keep a look out.
Good luck.