Manufacturer’s part number is EC12E2424407 and it seems to obsolete here in the US, at least according to Mouser. Here is a link to what they’re (Mousers) computers find as similar…
http://www.mouser.com/Search/Refine.aspx?FS=TRUE&N=4294759270+5502072+4294642686+1323043
Will any of these work or will I need to order the encoders from Farnell?
Thanks in advance!