Wow, that sounds like a killer property.
Just got done pouring through a few scenarios, and it appears Countrywide will buy it on their subprime programs, (assuming they understand the nature of your property and about 1,000,000 other stipulations) of which with your credit rating they have killer deals. Subprime not only deals with odd credit and income scenarios, but also unique property situations - of which this qualifies. The guidelines do state that they WILL buy a non-insurable assuming a few things though.
Please note, I'm not actually licensed in MA so I don't have the state specific guidelines here. There could be a snag - I ran the scenario assuming it's in WA and got a 5% down approval, 1st 30 / Fixed @ 6.5% and HELOC 2nd @7% -
Interest only option payments on both available which will drop the payment if wanted.
The rates will be slightly higher, but it's not the end of the world, given the nature of rates today, in a few years this will look like a good deal.
Price to pay for paradise. Either way, try
WWW.Countrywide.com.
Good luck!
Randy