My 1860s house has an OLD Green Colonial furnace (coal converted to gas). The bellows in the diaphram have shot craps and desperately need to find a replacement (bellows OR whole diaphram). The furnace is marked '927' near the top/front, and on the door it says 'Type O'. The diaphram is a Low Blast Model 150C Economite, Serial 90324. I have to get a whole new furnace if I can't find this part - help!! Thanks Dana