truth is I dont know actually.what the real differences is in those ploughs i was about to ask the same question myself.Just wandered, in what way is the TS 59 E different? Is the cross shaft longer or something? To my knowledge the 'E' and the 'J' are the same plough, they both have cast cross shaft brackets at the front but the beam that supports the middle of the frame is slightly different and, the front furrow width adjuster collars are a little different. The 'M' is the same as the 'J' but, has steel brackets to hold the cross shaft, rather than cast.
better to ask someone else ie @wuddy .
but anyway ours has the ordinary steel 2 hole bracket not a cast one so must be an M then like that??
the serial no. plate disappeared on it yrs ago so i don't really know.