Hello, I am looking for the early version Service & Repair manual and Parts manual, this one has to cover model < SN 512816000 if anyone has one in .pdf form or even in print they can let go for a price let me know. I have a manual that specs the 853C. > SN 512816000 thru 51282XXXX but there were some changes when they incorporated BICS and BOSS system along with control relays and interlocks. I can be contacted at : [email protected] Thanks, JLM