Green Colonial furnace, need parts

HELP - GETTING DESPERATE FOR INFO! THIS SITE IS MY LAST RESORT! I have an old Green Colonial furnace (from Des Moines, IA, out of business in 1975) (coal converted to gas) and the bellows have shot craps in the diaphram. The only markings I can find on furnace is "927" at top front; and "Type O" on the door. The diaphram is a "Low Blast Model 150C Economite, Serial 90324". The bellow is approx. 5" in diameter with small hole in center to seat into diaphram. I know this is an antique, but if I can't find this part I'll need a whole new furnace. If your company doesn't have parts, can you give me any leads to find it? thanks so much! Dana

What is if for? Do you have or can you post a picture? Is it a hot air or boiler?

Thanks