I have been gathering information on how to clean and properly lubricate a DEC PC05 and an ASR 33. The teletype manual calls out KS-7470 oil and KS-7471 grease. Googling, I find that there are a great number of lubricants with KS numbers. What is the origin of this number? It seems like it is some kind of directory of lubricants, but I can't find a listing. I found a cross for KS-7471 in an old AT&T purchasing document, but none for KS-7470. -chuck