I've been dealing with them on the 'work' Partner 4, and they have been very easy to deal with, and cheap, for what they are doing.
Worth a call, IMO.
FWIW, the Two Partner 4 books that I have seen, mine, and the one at work, the drawings look about like third generation photocopies. The numbers are tough to read if they can be read at all, and, well, you are going to end up dealing with them anyways...Might as well check.
The two I deal with use a pneumatic cylinder to release a pull stud puller. Dunno what the machines without a pushbutton tool change use.