No, and we tried really hard. I left a lot of detail out of my story, because it wasn't really the point, but we hired lawyers, Lenny willed the property to me, and we even attempted a legal trust arrangement while he was still living. But despite the fact that we were registered domestic partners, nothing worked.
The agreement Lenny signed when he bought the property was contractually binding, and the only way around that was to get the co-op board to rewrite the agreement.
They would not do that, citing fears that people on long waiting lists would sue them.
This is a very good example of why actual marriage matters. Civil partnerships and other alternatives often conflict with the definitions in binding legal contracts. If the contract says marriage, then that's what counts. I think a lot of people don't really understand this.