Clutches and clutch linings are the same....Manual is written for both the 600/610 (also E & D). Years ago I replaced a broken axel and the drive gear with parts from a "basket" 600/610??? (I think) Immediately broke chains and bent all sorts of things.....on closer inspection I discovered the drive gear had a different tooth count then the others in the machine so I always count teeth now. Old Machinist.....I didn't know the pumps were different (interesting)....weight makes sense as the 610 was a 'reenforced' machine. Also, do you know if the differences in the "upright" are model specific.....one has an "eye hook" (as best as I can describe it) and the other has a heavy strap steel running from one upright to the other. It seems I've only seen the "eye hook" design on M-600s