In another thread a few days back there was some discussion about a stock jack for an M715 and Jon, you described one you'd seen. Look anything like the two pictured here?:
These are house moving jacks, as I was told, but I suspect they are probably more like old equipment jacks as they look smaller than the old house jacks I have seen in the past. Most of those were about 24 inches tall or better. These are 12 inch high bodies, and the threads will go up to about 22 inches of total height.