Just reading my manual for my (1985) PE insert. Combustor Option *CC35 can be customer as well as factory installed. Of course good luck getting that combustor these days. Also, it says, *(this option must be installed before insert is placed in fireplace opening). What a "pain in the ass" that would be. as the insert is bolted into the new SS Liner. Anyway, it goes on to say remove baffle plate,etc,etc. So it can be used with or without the combustor,since it obviously came with a baffle plate. That I have since dutifully replaced. Were there other makes and models at that time that are like this one? Also, it says that the catalytic combustor will: Reduce creosote up to 90% and increase efficiency up to 20%. Is that true? Any comments would be appreciated. @by the way,even though I managed to dig up the manual, there is no model or serial number on any of the pages.The only way to get it would be to pull the insert and look on the sides.