With the information on the unit, contact the mfgr.! Also, you can ask the previous home owners for paperwork that came w/the unit. If they don't have it, find out where they bought it. If you didn't already buy the house, have your (or their) Realtor contact the homeowners.
My best to ya and hope this helps.
PS: I haven't heard of Laurel but that doesn't mean they're out-of-business.