The list that bkay was referring to is for JA & JC numbers that are on Japanese made machines. It can be found at
http://www.doubleveil.net/zssmp/resources.htm#jajc The UHT & URR are Montgomery Wards model head numbers, which may or may not be used for the different manufacturers. It is possible that there are also JA and/or JC numbers on the URR & UHT machines.
Janey - Neat people never make the exciting discoveries I do.
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